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Materials and devices for energy and environment applications

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Advanced materials for fuel cells and electrolyzers

Introduction and scope:

For sustainable economic growth and environment protection, energy generated from renewable sources has to be converted and stored by highly efficient and ecofriendly ways. Fuel cell and electrolyzer technologies can be regarded as a promising solution to these urgent needs by providing the expected conversion efficiency.

Hydrogen and Fuel Cell technologies are considered as a key element in the future clean energy market. Today they are ready for application and large scale commercialization, although further cost reduction is expected for the next future to make them available at a suitable price. This means that new materials and optimized architectures able to increase durability, reliability and to reduce costs are necessary. This international symposium addresses issues of science, engineering, materials, systems, testing, applications and markets for all FUEL CELLS such as Solid oxide fuel cell (SOFC), Proton exchange membrane fuel cell (PEMFC), High Temperature Polymer Electrolyte Membrane fuel cell (HTPEM), Alkaline fuel cell (AFC), Phosphoric acid fuel cell (PAFC), Direct Alcohol Fuel cell (DAFC), Microbial Fuel Cell, Electrolyzers as well as HYDROGEN production, storage & infrastructure (H2PSI). The intention is to bring together the international community working on the subjects and to enable effective interactions between research and engineering communities. Although a Europe-bound event, participation is invited from all continents. It provides an excellent opportunity for scientists, engineers and manufactures to present recent technical progress and products, to establish new contacts in the appreciated networking events and to exchange scientific and technical information. The symposium is structured in eight different sections covering diagnostic techniques and systems design/components; catalysts and membranes for fuel cells and electrolyzers, electrochemical hydrogen pumps, etc.

Hot topics to be covered by the symposium:

  • MATERIALS FOR H2 PRODUCTION AND UTILIZATION;
  • PEFC CATALYSTS AND ELECTRODES
  • MATERIALS FOR ELECTROLYSIS TECHNOLOGY
  • SOFC’S MATERIALS
  • DIRECT ALCOHOL FUEL CELLS
  • ALKALINE FUEL CELLS
  • CELL DESIGN, STACK AND SYSTEM
  • MICROBIAL FUEL CELLS

Tentative list of invited speakers:

  • Nicolas ALONSO VANTE, UNIVERSITE' DE POITIERS, France
  • Lei BI WUHAN INSTITUTE OF TECHNOLOGY, China
  • Emiliana FABBRI, PAUL SHERRER INSTITUTE, Switzerland
  • Hubert GASTAIGER, TUM Technische Universität München, Germany
  • Pierre MILLET, CNRS, France
  • Elena PASTOR, UNIVERSIDAD DE LA LAGUNA, Spain
  • Eliana QUARTARONE, UNIVERSITA' DEGLI STUDI DI PAVIA, Italy
  • Thomas SCHMIDTH, ETH Zürich, Switzerland
  • Stefania SPECCHIA, POLITECNICO DI TORINO, Italy

 

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SESSION I : Luis Gerardo Arriaga
09:00
Authors : M.V. Martínez-Huerta, M. Roca-Ayats, G. García
Affiliations : Institute of Catalysis and Petrochemistry, CSIC. Marie Curie 2. E-28049 Madrid, Spain; Institute of Catalysis and Petrochemistry, CSIC. Marie Curie 2. E-28049 Madrid, Spain; University of La Laguna. Astrofísico F. Sánchez. E-38071 La Laguna, Tenerife, Spain

Resume : Direct alcohol Fuel Cells (DAFCs) and Unitized Regenerative Fuel Cells (URFCs), as efficient, clean and promising power sources, have attracted extensive attention due to their low operating temperature, high energy density and simple structure. However, for the implementation of these technologies, the development of good electrocatalysts for alcohol oxidation, oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is necessary. Pt-based materials are being commonly used because of their unique catalytic activity. The nanoparticles are usually supported in electrical conductive carbons in order to increase the accessibility of the active sites. But carbon is not stable enough, as suffers from corrosion at higher potentials. For that reason, it is necessary to develop new materials to be used as electrocatalytic supports. Herein, titanium metal nitrides and carbides, have been tested as catalyst supports because of their high electrical conductivity, low price and high corrosion resistance. Several Pt-based nanoparticles supported on TiC, TiCN, TiN and C have been investigated for CO, methanol and ethanol electrooxidation in the anode electrode, and for ORR and OER in the oxygen electrode in an URFC. Acknowledgements This work has been supported by the Spanish Science and Innovation Ministry under project ENE2014-52158-C2-1-R. MR acknowledges to the FPU-2012 program for financial support.

Q.1.1
09:30
Authors : A.Perego 1-2, Giorgio Giuffredi 2, Andrea Casalegno 2 and F. Di Fonzo 1
Affiliations : 1:Center for Nano Science and Technology @Polimi, via G.Pascoli 70/3, 20133 Milano, Italy 2: Dipartimento di Energia, Politecnico di Milano, Via Ponzio, 20133 Milano, Italy

Resume : To overcome the high cost of the catalyst in Direct Methanol Fuel Cell (DMFC) technology, research is moving towards the reduction in the Pt loading in the electrodes by increasing the electrochemical surface area. To date, the state of the art of catalyst supports is dominated by mesoporous carbon. It shows high conductivity but suffer from stability issues especially on long term operation. As shown in various works, titanium nitride (TiN) has a metal-like conductivity with an outstanding chemical stability, making it a possible candidate to replace carbon. In this contribution, we report about Pt-TiN catalysts support with self-assembled, hierarchical mesoporous nanostructure, grown by Pulsed Laser Deposition. This approach controls the gas dynamics of the nanoclusters-inseminated supersonic jet in order to differentiate the resulting impaction deposition, affecting the growth of the film. We demonstrate that with our technique, morphology can be controlled at the nanoscale. Electrochemical characterization towards DMFC reactions show it is possible to maximize platinum ECSA while controlling the porosity and the morphology of the material down to the nanoscale, minimizing metal ripening phenomena. These results show the potential of a PVD based technique that opens the doors of the nanoscale to the fabrication of high performing electrodes whose morphological and electrical properties are easily tuned. This approach holds promises for the highest level of Pt utilization.

Q.1.2
09:45
Authors : Dario R. Dekel, Hamish A. Miller
Affiliations : Dario R. Dekel, Technion - Israel Institute of Technology; Hamish A. Miller, CNR-ICCOM

Resume : Alkaline Anion Exchange Membranes (AEMs) for fuel cells have been rapidly developed. Latest improvements done in this technology are impressive, and some of the new developed AEMs already reached anion conductivities close to those of proton conducting Nafion for PEM-FCs. In the past three years an increasing number of research work has been published, showing that performance of AEM-FCs is getting higher and very promising. However, in spite of the potential hope of alkaline AEM-FCs to replace Pt metal for another less expensive electrocatalysts, there is no work showing AEM-FCs based on electrodes with zero-loading of Pt electrocatalyst. While with high loadings of non-Pt catalysts for ORR it was possible to replace Pt at the cathode, the kinetics of HOR in alkaline medium seems to be so slow in AEM-FCs, that to replace Pt at the anode electrode is very challenging, and normally high Pt-loadings has been used in this technology. Today, these facts are not so widely recognized and studied. Whereas research on ORR electrocatalysts in the alkaline medium has only recently begun, studies on HOR electrocatalysts for AEM-FCs still constitute an entirely unexplored field. In this talk the state-of-the-art of AEM-FC will be discussed, and a new high performance non-platinum HOR electrocatalyst for novel Pt-free AEM-FCs will be presented. The anode electrocatalyst consist of a C-ceria composite matrix decorated with low loading of Pd nanoparticles. AEM-FC performance using this electrocatalyst shows peak power densities of 0.5W/cm2, representing a worldwide record in performance of a Pt-free AEM-FC.

Q.1.3
10:00
Authors : Rhiyaad Mohamed,1 Tobias Binninger,2 Alexandra Patru,2 Kay Waltar,2 Eike Gericke,3 Xenia Erler,3 Emiliana Fabbri,2 Armin Hoell,3 Pieter Levecque1 and Thomas J. Schmidt2
Affiliations : 1HySA/Catalysis Centre of Competence, Centre for Catalysis Research, Department of Chemical Engineering, University of Cape Town, 7701, South Africa; 2 Paul Scherrer Institut, Electrochemistry Laboratory, 5232 Villigen PSI, Switzerland; 3Institut für Nanospektroskopie, Helmholtz-Zentrum für Materialien und Energie, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany

Resume : Polymer electrolyte fuel cells (PEFCs) are alternative energy conversion devices that may be used for mobile, stationary and portable applications in an environmentally friendly manner. These devices operate with the benefit of high power densities, higher efficiencies than conventional combustion engines and allow for quick start-up and shut-down [1]. However, current state of the art catalysts comprising Pt nanoparticles supported on high surface area carbon undergo a range of degradation phenomena, particularly during the start-up and shut down events flanking normal operation. Degradation of the electrocatalyst leads to a loss of the electrochemically active surface area (ECSA) of the Pt nanoparticles ultimately leading to fuel cell performance losses [2], which still presents a major hurdle to the widespread availability of commercial applications. The use of chemically robust, conductive metals oxides in their thermodynamically favorable oxidation states as support materials has become of particular interest to overcome this challenge [3]. Antimony doped tin oxide (ATO, Sb-SnO2) in particular was identified as a promising support material with enhanced stability towards corrosion under fuel cell operating conditions [4]. Insight into this enhanced stability can be achieved by using in situ anomalous small angle X-ray scattering (ASAXS) in conjunction with electrochemical testing of the supported catalyst. By doing so changes in the particle size distribution of the Pt nanoparticles can be monitored with potential cycling [5]. In this study we have deposited Pt nanoparticles on ATO by an in-house developed organo-metallic chemical deposition method [6]. The resultant Pt particle size distribution and dispersion on the support was determined by transmission electron microscopy (TEM). The ECSA of the Pt/ATO catalysts was measured by hydrogen underpotential deposition using cyclic voltammetry (CV) in nitrogen saturated 0.1 M HClO4 in a conventional three electrode compartment glass cell as well as an electrochemical three electrode flow cell used for the in situ ASAXS experiments. For the durability studies, the catalysts were exposed to 1000 potential cycles between 0.5 and 1.5 VRHE (vs. reversible hydrogen reference electrode, RHE) using a scan rate of 50 mV s-1 at room temperature. In order to understand the degradation phenomena of the Pt nanoparticles, CV’s between 0 and 1 VRHE as well as in situ ASAXS measurements were recorded at fixed intervals. TEM analysis was performed on the spent catalyst. The stability of the oxide supported Pt nanoparticles compared to carbon supported catalysts deposited by the same technique will be discussed. References [1] J.H. Wee, Applications of proton exchange membrane fuel cell systems, Renew Sust Energ Rev, 11 (2007) 1720-1738. [2] T.J. Schmidt, Polymer Electrolyte Fuel Cell Durability, in: F.N. Büchi, M. Inaba, T.J. Schmidt (Eds.), Springer Science and Business Media LLC, New York, 2009. [3] A. Rabis, P. Rodriguez, T.J. Schmidt, Electrocatalysis for Polymer Electrolyte Fuel Cells: Recent Achievements and Future Challenges, Acs Catal, 2 (2012) 864-890. [4] E. Fabbri, A. Rabis, R. Kotz, T.J. Schmidt, Pt nanoparticles supported on Sb-doped SnO(2) porous structures: developments and issues, Phy Chem Chem Phys, 16 (2014) 13672-13681. [5] T. Binninger, M. Garganourakis, J. Han, A. Patru, E. Fabbri, O. Sereda, R. Kotz, A. Menzel, T.J. Schmidt, Particle-Support Interferences in Small-Angle X-Ray Scattering from Supported-Catalyst Materials, Physical Review Applied, 3 (2015) 024012. [6] S. Taylor, E. Fabbri, P. Levecque, T.J. Schmidt, O. Conrad, The Effect of Platinum Loading and Surface Morphology on Oxygen Reduction Activity, Electrocatalysis, (2016) 1-10.

Q.1.4
10:15
Authors : B. López-Gonzáleza, A. Moreno-Zuriaa, F.M. Cuevas-Muñiza, M. Guerra-Balcázarb, J. Ledesma-Garcíab and L.G. Arriagaa*
Affiliations : aCentro de Investigación y Desarrollo Tecnológico en Electroquímica, 76703, Querétaro, México. bDivisión de Investigación y Posgrado, Facultad de Ingeniería, Universidad Autónoma de Querétaro Cerro de las campanas s/n, 76010, Santiago de Querétaro, México

Resume : The aim of this work is the synthesis of gold nanoparticles for the Glucose oxidation reaction in neutral media in order to use a cell culture medium like energy source for its glucose content. The Au/C was synthetized by chemical reduction method and evaluated for GOR by cyclic voltammetry in phosphate buffer pH 7.4 (PBS 7.4) and 10 mM glucose in PBS 7.4 solutions, the material exhibits a peak corresponding to the oxidation reaction which is located at approximately -0.15 V vs. NHE. In order to test the Au/C like an anodic material, an air-breathing microfluidic fuel cell (AB-FFC) was constructed by micromachining techniques and evaluated with Au/C as anode for the oxidation of glucose and Pt/C for the oxygen reduction reaction, these materials were deposited into toray paper by spray method. The AB-FFC reached an OCP value of 0.87 V and a power density of 5.08 mW cm-2 in alkaline medium, which is a good performance for a miniaturized fuel cell. In addition, DMEM / F-12 (cell culture medium, 17.5 mM glucose) was evaluated like anolyte solution obtaining 0.51 V and 1.65 mWcm-2. These results shown that the Au/C can be used like anodic material in neutral media with good performance and can even harvest energy from the cell culture medium.

Q.1.5
10:30 Coffe Break    
 
SESSION II : Carmen Rangel
11:00
Authors : G. Dispenza, L. Andaloro, F. Sergi, G. Napoli, N. Randazzo, S. Di Novo, S. Micari, V. Antonucci
Affiliations : National Research Council of Italy - Institute of Advanced Energy Technologies Via Salita S. Lucia sopra Contesse, 5, 98126 Messina, Italy.

Resume : The present abstract describes the design, realization and validation of a solar powered hydrogen fueling station in smart cities applications. CNR-ITAE together with other industrial partners has developed, under the Italian research project called i-NEXT (innovation for greeN Energy and eXchange in Transportation), the on-site hydrogen production plant. The plant is fed by a micro grid able to receive energy, from solar radiation by a 100 kW roof-top photovoltaic plant and connected with a battery energy storage of 300 kWh (composed by 16 sodium nickel chloride high temperature batteries) and it is able to deliver hydrogen and electricity for an electric and hydrogen vehicles fleet. The hydrogen plant consists of four sub systems: hydrogen production by electrolysis, compression system, high-pressure storage system and hydrogen dispenser for automotive applications. The experimental plant is able to generate in the hydrogen production sub system, through alkaline electrolyzer of 30 kWh: 6,64 Nm3/h of H2 with a gas purity of 99,995% (O2 < 5ppm and dew point < -60°C). The compression sub system consisted by three stage compressor with gas flow rate of 5,2 Nm3/h and a delivery pressure of 360 bar. After that, the compressed H2 gas is stored in high-pressure tanks of 350 liters capacity allowing, in this way, a supply through dispenser system of two automotive’s tank of 150 liters @ 350 bar in less than thirty minutes. This paper shows the design, the development and the efficiency results coming from a first test campaign.

Q.2.1
11:30
Authors : NAN YANG[1] and CARMELA ARUTA[2]
Affiliations : [1] Shanghai Technology University, Shanghai, China [2] National Research Council CNR-SPIN Rome, Italy

Resume : Undestanding the effect of defect associations in ion conductivity and surface reactivity is particularly important for energy and electronic applications such as micro-solid oxide fuel cells, sensors and memristors. In this presentation, we will show a comparative study investigating ionic conductivity and surface reactions for well-grown epitaxial SDC films varying the samaria doping concentration. With increasing doping above 20 mol% of samaria, an enhancement in the defect association was observed by Raman spectroscopy. The role of such defect associates on the films’ oxygen ion transport and exchange was investigated by electrochemical impedance spectroscopy and electrochemical strain microscopy (ESM). [1] The measurements reveal that the ionic transport has a sharp maximum in ionic conductivity and drop in its activation energy down to 0.6 eV for 20 mol% doping. Increasing the doping concentration further up to 40 mol%, raises the activation energy substantially by a factor of two. [2] We ascribe the sluggish transport kinetics to the "bulk" ionic-near ordering in case of the heavily doped epitaxial films. Analysis of the ESM first order reversal curve measurements indicate that these associated defects may have a beneficial role by lowering the activation of the oxygen exchange "surface" reaction for heavily doped 40 mol% of samaria. We reveal in a model experiment through a solid solution series of samaria doped ceria epitaxial films that the occurrence of associate defects in the bulk affects the surface charging state of the films to increase the exchange rates. Implication of these findings are the design of coatings with tuned oxygen surface exchange by control of bulk associate clusters for future electro-catalytic applications. [1] Nan Yang et al. ACS Nano 8, 12494 (2014). [2] Nan Yang et al. submitted (2016)

Q.2.2
11:45
Authors : Paweł Stelmachowski1,2, Alessandro H.A. Monteverde Videla 1, Andrzej Kotarba2, Stefania Specchia1
Affiliations : 1 Politecnico di Torino, Dept. of Applied Science and Technology, Torino, Italy 2 Faculty of Chemistry, Jagiellonian University in Kraków, Kraków, Poland

Resume : The production of a chemical vector (hydrogen) by a reliable way is one of the major concerns for the hydrogen economy. The electrolysis of water is a clean way to produce hydrogen and oxygen,without production of contaminant gases,avoiding further separation systems. This reaction is not thermodynamically favorable and thus requires the use of catalyst and energy input. The development of uncostly and based on cheap raw materials catalysts, capable of competing with active but expensive noble metal-based catalysts, has been the focus for this application during the last years. From the economically practical point of view, electro-splitting of water is only a feasible option when electricity is coming from non-convectional, renewable energy sources. Rechargeable metal−air batteries or fuel cell air electrodes require catalysts for the oxygen evolution reaction (OER). Electrochemical water splitting is associated with substantial energy loss,mainly due to the high over-potentials at the oxygen-evolving anode. First-row transition metals,specifically spinel and perovskite oxide materials exhibit encouraging activities in basic conditions, especially those based on cobalt and nickel with iron addition. Micro and mesoporous silicas were used as templates to obtain catalytic materials based on NiCo2-xFexO(0

Q.2.3
12:00
Authors : Atef Zekri, Martin Knipper, Jürgen Parisi, Thorsten Plaggenborg
Affiliations : Energy and Semiconductor Research Laboratory, Department of Physics, University of Oldenburg, Carl-von-Ossietzky Strasse 9-11,26129 Oldenburg, Germany

Resume : Solid Oxide Fuel Cells (SOFC) convert chemical energy from hydrogen-rich fuels into electrical power under high temperature (from 700 °C to 900 °C). Due to their high efficiency, low emissions and long-term stability, SOFC are becoming of increasing interest as energy conversation devices. However, in order to maintain the SOFC system performance and avoid critical impacts of the operation conditions on the durability and reliability of SOFC devices, this clean technology is getting more complex in terms of composition and microstructure. One of the main challenges is to overcome the degradation in the microstructure of the anodes due to the extreme operating conditions. In this study we investigated SOFC anodes consisting of porous metal (nickel) and ceramic material (gadolinium doped ceria) at long operation times (2500 h-20000 h) using SEM, EDX-mapping and -line-scanning. The anodes were taken from various stacks aged under realistic working conditions (850 °C). Qualitative and quantitative analysis of the nickel distribution in the anodes were applied. Nickel depletion was observed in the anode/electrolyte interface region. This Nickel depletion increases with the operation time. Furthermore the nickel agglomeration in the contact layer as well as in the functional layer is analysed and discussed. Keywords: SOFC, Degradation, Microstructure, Nickel Depletion, Agglomeration, Long-term operation, EDX, Mapping, Line Scanning.

Q.2.4
12:15
Authors : G. Napoli, L. Andaloro, F. Sergi, G. Dispenza, S. Micari, N. Randazzo, V. Antonucci
Affiliations : National Research Council of Italy - Institute of Advanced Energy Technologies; Via Salita S. Lucia sopra Contesse, 5, 98126 Messina, Italy,

Resume : Many actions have been recently carried out within European cities with the aim of reduce the negative impacts on traffic and environment caused by transport. New technologies for vehicles and traffic management will be the key to lower transport emissions and the electric approach is a promising line to achieve EU’s emissions reduction target for 2030 and 2050. Electric Vehicles (EVs) include vehicles with different technologies such as Battery Electric Vehicles (BEVs), Fuel Cell Vehicles (FCV) or Hybrid Electric Vehicles (HEVs). BEVs operate purely on the battery power but the energy storage system remains one of the main critical elements due to vehicle autonomy, weight and charging time. FCV outperform BEV for its high autonomy and it is possible to perform a hydrogen recharge in short time but the costs remain high. Different from these last, hybrid configurations show advantages for both technologies if hybridization is carried out without an internal combustion engine but through a Fuel Cell System (FCS). Within an Italian research project, CNR TAE Institute has been involved in a Fuel Cell Hybrid Electric Vehicle (FCHEV) development for public transportation. The hybrid vehicle provides the use of a FCS that distributes the electrical power in the connection between batteries and traction inverter via a DC/DC converter for the extension of the daily autonomy with respect to pure electric mode. This work presents the development phases of the powertrain and preliminary on road tests.

Q.2.5
12:30 Lunch Break    
 
SESSION III : Antonino Aricò
14:00
Authors : Thomas J. Schmidt
Affiliations : Electrochemistry Laboratory, Paul Scherrer Institute; Laboratory for Physical Chemistry, ETH Zürich

Resume : Oxygen electrodes are playing a key role in electrochemical energy conversion devices such as fuel cells and water electrolyzers. In both acidic and alkaline environment, both the oxygen reduction and oxygen evolution reaction (ORR and OER), respectively, are limiting the overall energy/voltage efficiency due to its sluggish kinetics. [1, 2] Whereas in acidic environment, mainly precious metals are used to catalyze the ORR (e.g., Pt or its alloys) or the OER (e.g., IrO2), the variety of possible catalysts in alkaline electrolyte is significantly increased and also many metal oxide based systems can be employed. Generally the oxygen reduction or evolution mechanisms are only partly understood independent of the electrolyte environment and material used. In order to help to understand the underlying mechanisms for the two reactions and to support the experimental results, very often computational methods are used, mainly using density functional theory (DFT) calculations. Similar approaches are also used for gaining insights into catalyst stabilities under operational conditions. In this talk, some of your recent findings on noble and non-noble metal catalysts will be presented. References [1] A. Rabis, P. Rodriguez, T.J. Schmidt, ACS Catal., 2012, 2 (5), 864–890 [2] E. Fabbri, A. Habereder, K. Waltar, R. Kötz, T.J. Schmidt, Cat. Sci. Tech., 2014, 4, 3800-3821

Q.3.1
14:30
Authors : M. Santamaria, C. M. Pecoraro, F. Di Franco, F. Di Quarto
Affiliations : Electrochemical Materials Science Laboratory, DICAM, Università di Palermo, Viale delle Scienze, Ed.6, 90128 Palermo, Italy

Resume : To promote Proton Exchange Membrane Fuel Cells (PEMFCs) commercialization, large research effort has been devoted in developing new polymer electrolytes that can replace the usually employed proton conductors, e.g. Nafion®, with other membranes of comparable performances but lower cost. Chitosan (CS)-based membrane electrolyte is currently studied as alternative candidate for PEMFC application. Several works have shown that Heteropolyacids (HPAs) can be used to prepare Chitosan polyelectrolytes (PECs) to be employed as proton exchange membrane in low temperature fuel cell. In previous works [1-3] we have shown that CS/PTA membranes, prepared using alumina porous medium for the slow release of H3PW12O40, show good performances in H2 fed fuel cell. Notably, in ref. [4] CS/PMA membranes are reported to exhibit proton conductivity higher than that measured with CS/PTA. This paper in focused on the synthesis and characterization of CS/PMA and mixed CS/PMA-PTA membranes with the aim to assess the influence of HPA concentration and nature on their performance as proton conductors in H2 fed fuel cell. X-ray diffraction and FTIR analyses were performed to study the structure and composition of the membranes, while SEM was used to get information on the membranes morphology and thickness as a function of the preparation conditions. The membranes were tested in a H2/O2 fuel cell at room temperature. Impedance Spectroscopy was used to get information of the conductivity of the membrane and to model the overall electrical behaviour of the cell. 1 -M. Santamaria, J. Power Sources 276 (2015) 189 2 - C.M. Pecoraro, Int. J. Hydrogen Energy, 40 (2015) 14616 3 - M. Santamaria, Int. J. Hydrogen Energy, 41 (2016) 5389 4 - Z. Cui, J. Power Sources 188 (2009) 24

Q.3.2
15:00
Authors : C.M. Rangel and others
Affiliations : LNEG- National Laboratories for Energy and Geology Paço do Lumiar, 22 1649-038 Lisboa Portugal

Resume : xxx

Q.3.3
15:15
Authors : Wei Li, Xuefei Gao, Dehua Xiong, Wei-Guo Song, Lifeng Liu*
Affiliations : Wei Li; Dehua Xiong; Lifeng Liu: International Iberian Nanotechnology Laboratory Xuefei Gao; Wei-Guo Song: Institute of Chemistry, Chinese Academy of Sciences

Resume : Electrochemical water splitting into hydrogen and oxygen is a promising method for renewable energy storage. The development of ultrastable, efficient and low-cost bifunctional electrocatalysts that are active for both the hydrogen evolution (HER) and oxygen evolution reactions (OER) remains a huge challenge. Herein, the Co-Ni-P nanowires are presented as efficient and ultrastable Janus electrocatalysts for full water splitting. Self-supported Ni foam based electrodes (Ni@Co-Ni-P) covered with bifunctional Co-Ni-P nanowires are fabricated by hydrothermal process, followed by phosphorization using red phosphorous. The Ni@Co-Ni-P electrode exhibits outstanding electrocatalytic activity in alkaline solution towards HER, attaining a cathodic current density of 100 mA cm-2 with a small overpotential of 137 mV. It also shows superior catalytic performance towards OER, delivering a high current density of 90.2 mA cm-2 at an overpotential of 350 mV, outperforming many transition metal based OER catalysts. Given the well-defined bifunctionality, an alkaline electrolyzer is assembled using two symmetrical Ni@Co-Ni-P as the cathode and anode, respectively. The electrolyzer exhibits an energy efficiency as high as 91% at 10 mA cm-2, and retains an efficiency of 64% even at 240 mA cm-2. Such electrolyzer is able to operate for 3175 h under 1.96 V without degradation delivering a current density of 100 mA cm-2, leading to exceptionally high H2 production rate of 311 mmol h-1 g-1 catalyst cm-2 with an energy efficiency of 76%. The extraordinary stability for overall water splitting results from structural integrity of the Ni@Co-Ni-P electrodes and formation of Co-Ni-P nanowire/(CoxNiy) hydroxide nanosheet core/shell nanostructure.

Q.3.4
15:30 Coffe Break    
 
SESSION IV : Vincenzo Antonucci
16:00
Authors : M. Cassir*, A. Nechache, A. Meléndez-Ceballos, V. Albin, V. Lair, A. Ringuedé
Affiliations : PSL Research University, Chimie ParisTech - CNRS, Institut de Recherche de Chimie Paris, 75005, Paris, France. michel.cassir@chimie-paristech.fr

Resume : High temperature fuel cells and electrolysers, based on solid oxides and/or molten carbonates, are still facing delicate problems, such as yields, durability and costs, which means improving electrode kinetics, degradation protection and new materials. The “all solid” solid oxide fuel cell (SOFC) is the most promising next-generation fuel cell regarding stationary power generation; however, this device requires a perfect control of interfaces at its high operation temperature (usually, at more than 750°C. SOFCs should work at lower temperatures (<650°C) without additional over potentials at the electrodes and a controlled electrolyte resistance (either due to the effect of a thin layer or to the properties of a new material). In the case of the molten carbonate fuel cell (MCFC), the key issue is to control the corrosion mainly of the cathode and the bipolar plates and to increase the power density. In both SOFC and MCFC generators, thin functional layers constitute a key issue for improving interface reactions and building new architectures. The role of micro- or nano-strutured thin films can be diverse: protective layers for MCFC (carbonate corrosion) and SOFC (diffusion or electronic barriers), bond layers between electrodes and interconnects and catalytic layers. Moreover for SOFCs, thin-layered electrolytes can be envisaged for micro fuel cells systems as well as active electrolyte or electrode layers to improve both charge and mass transport. We are commonly using electrodeposition and Atomic Layer Deposition (ALD), processing conformal, adherent and homogeneous layers [1]. Crystalline layers can be obtained by ALD at T<300°C without annealing treatments. We will show, in particular, that epitaxial as-deposited ALD layers of ceria enhance the reactivity of this oxide towards hydrogen oxidation [2]. The properties of protective thin layers at the MCFC cathode will be also be outlined by significant results [3]. In this presentation, on the basis of our works and the literature, we will also introduce recent results on solid oxide electrolysers (SOEC) including thin functional layers [4]. New high-temperature fuel cells concepts will be introduced, such as composite electrolyte oxide/carbonates combining MCFC/SOFC electrolytes and new ideas such as proton and oxide electrolytes. Finally, we will show the general input of high-temperature devices in the energy field, including CO2 electrochemical valorisation [5]. References: 1. M. Cassir, A. Ringuedé, L. Niinistö, J. Mater. Chem., 20, 8987 (2010) 2. A. Marizy, P. Roussel, A. Ringuedé, M. Cassir, J. Mater. Chem. 3, 10498 (2015) 3. A. Meléndez-Ceballos, V. Albin, A. Ringuedé, S. M. Fernandez-Valverde, M. Cassir, Int. J. Hydrogen Energy, 39, 12233 (2014) 4. A. Nechache, M. Cassir, A. Ringuedé, J. Power Sources 258, 164 (2014) 5. M. Cassir, S. McPhail A. Moreno, Int. J. Hydrogen Energy, 37,19345 (2012)

Q.4.1
16:30
Authors : Massimiliano Lo Faro, Sabrina C. Zignani, Stefano Trocino and Antonino S. Aricò
Affiliations : Institute of Advanced Energy Technologies (ITAE) of National Research Council (CNR), Via Salita S. Lucia sopra Contesse 5, 98126 Messina, Italy

Resume : This communication complies with the general trend on SOFC about the utilization of low cost fuels. A possible scenario for the near future is the direct utilization of biofuels in SOFC stack. At the present, the conventional Ni-YSZ/YSZ/YDC/LSFC cells are affected from several constraints in the direct utilization of such fuels mainly consisting in the carbon formation and sulphur contamination of the anode. For this reason, in the short and medium terms a possible solution to these issues is the utilization of a barrier layer attached to the outermost side of the anode. At this scope, the pre-layer materials must show properties that may comply requirements such as mechanical, thermal and electrochemical properties at least similar to the Ni-YSZ. In addition, the catalyst must be deposited at very thin level in order to mitigate the ohmic constraint of an addition layer. Ni-based alloys (Ni-M, M=Ni, Co, and Fe) in combination with gadolinia-doped ceria is reported to be a valuable material for the oxidation of biofuels including the oxidation of sulphur compounds. Therefore, the investigation of such catalysts as protective layer becomes of interest in order to maintain the well established manufacturing technology around the SOFCs. With this preface, this communication will report the strategy adopted for the preparation of catalyst with a proper composition at the atomic level, the catalytic properties and physico-chemical properties of catalyst, as well as the electrochemical investigation of performances for the protected cells in comparison to that achieved for a bare cell.

Q.4.2
17:00
Authors : Mariusz Krauz, Ryszard Kluczowski, Michał Kawalec
Affiliations : Institute of Power Engineering Ceramic Department Cerel, Research Institute

Resume : Since 2004 the Ceramic Department CEREL at the Institute of Power Engineering researched and developed high variety of SOFC, both electrolyte and anode supported, ranging from 10 mm electrolyte and anode supported button cells through 50x50mm 1.2 mm thick anode supported SOFC to full 100x100 mm 0.5 mm thick AS-SOFC. The best obtained electrical result was 1.25 W/cm2 at 800 °C. Electrolyte Supported Solid Oxide Fuel Cells are manufactured in IEn OC CEREL using two technologies: electrolyte is made by tape casting, whereas anode and cathode layers are applied by screen printing. Anode supports for Anode Supported Solid Oxide Fuel Cells (AS-SOFCs) are produced by two different methods: traditional method of tape casting and more novel high-pressure injection molding. Other necessary layers are produced using a screen printer or ink-jet printer.

Q.4.3
17:15
Authors : Barbera Orazio, Briguglio Nicola, Cipitì Francesco, Giacoppo Giosuè
Affiliations : CNR – ITAE – Institute for Advanced Energy Technologies “Nicola Giordano” Salita S. Lucia sopra Contesse 5, Messina 98126, Italy

Resume : Generating electric power using hydrogen is becoming a real hope; thanks to hydrogen technologies, climate challenges might be overcame and our towns would be free of pollutants and noise. For this reason, research and development of hydrogen technologies are fundamental to accelerate their introduction on the market as soon as possible. Starting from the electrochemical process, that allow electricity production, research activity has to be addressed to the design of fuel cell, which is the device “containing” the electrochemical package. In this field, namely in fuel cell stack research, the authors have developed a reliable methodology for stack design and test, over 15 years of experience. Prototyping is the direct expression of the research activity, carried out on the device, which allow the lab scale technology to be transferred on the real use. Due to that, research on fuel cells started studying the design methodology, has passed through the manufacture of the devices, until to experimental tests. In this way the issues related to the fuel cell stack “structure” can be highlighted and both the design methodology and, consequently, the manufacturing, improved. In this work, the authors illustrates how prototyping activity on fuel cell stack permitted the manufacturing of several prototypes, conceived for different applications (stationary, space, cogeneration in combination with reformer). Moreover, the improving in power and reliability of the devices and the problems encountered during research activities will be discussed.

Q.4.4
 
POSTER SESSION : Vincenzo Baglio
17:30
Authors : Marisol Tapia-Rosales1, Pierre-Alexandre Pascone2, José Luis Sosa-Sánchez1, Dimitrios Berk2, Norma Yadira Mendoza-Gonzalez2, Javier Martínez-Juárez1
Affiliations : 1Posgrado en Dispositivos Semiconductores, Instituto de Ciencias de la Benemérita Universidad Autónoma de Puebla, Blvd. 14 Sur y Av. San Claudio, Ciudad Universitaria Puebla, Puebla, México 2Plasma Processing Laboratory (PPL), Department of Chemical Engineering, McGill University, 3610 rue University, Montreal, Quebec, H3A 0C5, Canada

Resume : It is well known that, it is almost impossible to realize the large-scale practical application of fuel cells unless the expensive noble metal-based electrocatalyst for the oxygen reduction reaction (ORR) is replaced by other low-cost and stable electrocatalysts which can provide similar performance. In this work, nitrogen functionalized graphene nanoflakes (N-GNFs) decorated with metal (cobalt or iron) phthalocyanines (MPcs) through π- π interactions act as non-noble metal electrocatalysts with a good activity and stability for the ORR in a neutral media. The properties of the electrocatalysts obtained were examined by X-Ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FTIR), Raman spectroscopy (RS) and X-ray photo-electron spectroscopy (XPS). The electrocatalytic activity of N-GNF/MPcs towards the ORR was evaluated using the rotating disk electrode (RDE) method. The results showed an improvement in electrocatalytic activity for the N-GNF/FePc catalysts with an onset potential at 0.65 V vs. RHE in a 0.1 M H2SO4 solution at 2500 rpm and for this reason they can be used as cheaper Pt-free ORR catalysts. The improved electrochemical activity is mainly attributed to the inherent properties of graphene and its π -stacking interaction with the FePc material which is favoured by the planar structure of both materials.

Q.4.5
17:30
Authors : Poplavsky V.V., Dorozhko A.V., Matys V.G.
Affiliations : Belarusian State University of Technology

Resume : Active layers of the electrocatalysts for oxidation of methanol and ethanol were prepared by ion beam assisted deposition (IBAD) of platinum and activating rare earths metals (Ce, Yb) onto carbon (AVCarb® Carbon Fiber Paper Р50 and Toray Carbon Fiber Paper TGP-H-060 Т) supports. The deposition method is characterized by the use of deposited-metal ions as assisting ions. Metal deposition and mixing between the precipitable layer and surface of the substrate by accelerated ions of the same metal were carried out on the experimental unit from a neutral vapor fraction and the vacuum-arc discharge plasma of a pulsed electric arc ion source, respectively. Ion accelerating voltage is 10 kV; vacuum – 10^–2 Pa. Investigation of the composition and microstructure of layers was carried out by RBS, SEM, EPMA and XRF methods. It has been established that the obtained catalytic layers contain atoms of the deposited metals and substrate material; their thickness reaches ~30–100 nm. Content of platinum atoms in the layers is ~2×10^16 cm^–2, concentration of deposited metals atoms in the maximum of distribution equals about a few at.%. According to cyclic voltammetry investigations of the electrocatalysts with prepared layers exhibited high catalytic activity in the reactions of electrochemical oxidation of methanol and ethanol. In comparison with the traditional multistage chemical methods of preparation of the deposited catalysts, the proposed IBAD method appears to be promising and often more preferable. Some experimental samples of membrane electrode assemblies with the prepared electrocatalysts and Nafion N 115 membrane have been created.

Q.4.6
17:30
Authors : Elisabetta Di Bartolomeo1, Caterina Sarno1, Igor Luisetto2, Simonetta Tuti2
Affiliations : 1Department of Chemical Science and Technologies, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy 2Department of Sciences, University of Rome “Roma Tre”, Via della Vasca Navale 79, Rome, Italy

Resume : Solid oxide fuel cells working make possible the use of hydrocarbons as fuel. The biogas might be employed as a renewable source for the reforming of methane because it contains CO2 as reforming agent. The CO2 reforming of CH4, otherwise known as dry reforming (DRM), is a strongly endothermic process that is operated at high temperatures to achieve suitable CH4 and CO2 conversions. The development of Ni (10 wt%) based structured and unstructured catalysts promoted by a small amount of Ru (0.05 wt%) for DRM has been investigated. Unstructured catalysts were prepared by wet impregnation method and a combination of wash coating-wet impregnation methods was used for cordierite monoliths. Samples were characterized by XRD, BET, H2-TPR, TEM, FE-SEM techniques and the catalytic activity for DRM was evaluated at 800 °C during time on stream. Chloride impurities deriving from the RuCl3 precursor negatively affected the catalytic activity of Ni-Ru unstructured catalysts. Ru promoted catalyst (Ni-Ru), free from chloride, was remarkable active and stable whereas Ni catalyst deactivated at high GHSV due to the formation of Ni2+-containing inactive phases. Ni-Ru monolith was initially much more active than monometallic Ni stating the positive effect of Ru on maintaining Ni reduced. Reaching steady state condition, Ni rapidly deactivated due to carbon formation, whereas Ni-Ru monolith remained stable confirming that Ru behaves as an efficient and cheap promoter of Ni for DRM.

Q.4.7
17:30
Authors : Cuicui Dong,Gongwen zou,Qiong Zhou
Affiliations : China University of Petroleum-beijing;China University of Petroleum-beijing;China University of Petroleum-beijing

Resume : The objective of this study is to develop a novel nanocomposition with high conductivity and low methanol permeability.High sulfonation degree sulfonated poly (ether ether ketone) (SPEEK) electrospun nanofiber were prepared by single spinneret electrospinning.Incorporation the nanofiber mats to the sulfonated poly(2,6-dimethyl-1,4-phenylene oxide)(SPPO) matrix provided mechanical stability and methanol-permeation resistivity.The performances of the composite membranes were characterized.The study showed that the proton conductivity of the composite membranes approximately 4 times higher than that of pristine SPPO,and their swelling ratios were below 2%. All the data proved that the composite membranes to be potential for usages in PEMFC.

Q.4.8
17:30
Authors : Isabella Nicotera1, C. Simari1, C. Oliviero Rossi1, C. Lo Vecchio2, A.S. Aricò2, V. Baglio2
Affiliations : 1 Department of Chemistry and Chemical Technologies, University of Calabria, via P. Bucci, Cubo 14D, 87036 Rende (CS), Italy 2Istituto di Tecnologie Avanzate per l’Energia “Nicola Giordano” (CNR), via Salita S. Lucia sopra Contesse, 5 - 98126 Messina, Italy

Resume : Direct methanol fuel cells (DMFCs) are good candidates as power sources for portable and auxiliary power unit applications. They combine the merits of polymer electrolyte fuel cells fueled by hydrogen with the advantages of a liquid fuel, such as easy handling and high energy density. Despite these advantages, there are still technical barriers to overcome for their widespread commercialization, such as methanol crossover from anode to cathode through the proton exchange membrane. Methanol crossover leads not only to reduced fuel efficiency, but decreases the fuel cell performance due to the presence of a mixed potential at the cathode. In this work, composite membranes based on Nafion with the inclusion of layered double hydroxide (LDH) were used to increase the operating temperature of a DMFC. LDHs, of anionic clay family, consist of stacks of positively charged mixed metal hydroxide layers that require the presence of interlayer anions to maintain overall charge neutrality. Here, we focused on the preparation of LDH with Mg2+/Al3+ metal cations (with metal ratio 2:1) and NO3- as countervailing anion in the interlayer space. The dispersion of 2D platelike nanolayers in the polymeric matrix demonstrates to be a physical barrier, considerably reducing the methanol mobility through an increase of the tortuosity of the diffusional paths of methanol molecules. Furthermore, we show as different preparation methods of the nanocomposites influence morphology, transport and barrier properties. These effects are presumably dependent on some preferential orientation induced to the nanocaly platelets within the polymer matrix. Therefore, the high hydrophilicity of the nanoadditives is expected to be an effective method to improve the proton transport by promoting the Grotthus-type mechanism, while the membrane morphology is optimized by exfoliation and mechanical alignment of the LDH platelets in the polymeric matrix in order to increase the blocking effect at the methanol crossover. The electrochemical behavior of the hybrid nanocomposites was investigated in a single cell at different temperatures (from 90 to 110 °C), and the results were compared with those obtained on the filler-free Nafion membrane. Cell resistance measurements showed a significant improvement of the water retention capability at intermediate temperature for the composite membranes. This feature was investigated and explained by a thorough NMR study (diffusometry, relaxometry and 1H spectral analysis) on the different membranes.

Q.4.9
17:30
Authors : Bogusław Budner a, Waldemar Mróz a, Sergey Grigoriev b, Vladimir Fateev c, Michael Korwin-Pawlowski d, Yoshiyuki Suda e
Affiliations : a Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Street, 00-908 Warsaw, Poland b National Research University "Moscow Power Engineering Institute", Krasnokazarmennaya str., 14, Moscow, 111250, Russia c National Research Centre "Kurchatov Institute", Kurchatov sq., 1, Moscow, 123182, Russia d Université du Québec en Outaouais, Département d’informatique et d’ingénierie, 101 rue Saint-Jean-Bosco, Gatineau, (Québec), Canada e Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, Toyohashi, Aichi 441-8580, Japan

Resume : Results of the X-ray photoelectron spectroscopy (XPS) and corrsponding analysis of the oxidation degree of thin films of catalyst deposited using the pulsed laser deposition (PLD) are presented in this paper. Multilayer structures of nanometer thickness based on Pt/Pd, Pt/Ru and Pt/Co have been deposited at room temperature with an excimer ArF laser (л = 193 nm) on the gas-diffusion electrodes intended for operation as cathode or anode of proton-exchange membrane (PEM) fuel cells. The total weight of the deposited noble metals was from 4.76 to 9.50 mg/cm2 for the Pt/Pd structure, from 3.23 to 5.43 mg/cm2 for the Pt/Ru structure and from 3.81 to 5.23 mg/cm2 for the Pt/Co structure. Based on the results of XPS study the oxidation state of the deposited metals and the amount of contribution of oxidized metals in the deposited layers were determined. It was found that the results of quantitative analysis are very substantially dependent on the adopted model describing the shape of the bands in the XPS spectra and on the method of background cut-off. The corresponding model simulated the analyzed bands with high accuracy was developed based on the spectral measurements for pure metals and available literature.

Q.4.10
17:30
Authors : Natalia Lysunenko, Valentine Mokiychuk, Mykola Brychevskyi
Affiliations : Natalia Lysunenko, Mykola Brychevskyi, Frantsevich Institute for Problems of Materials Science of NASU, Krzhizhanivsky Str., 3, 03680, Kyiv, Ukraine; Valentine Mokiychuk, National aviation university, Kosmonavta Komarova, 1, Kyiv, 03058, Ukraine.

Resume : Solid oxide fuel cells (SOFC) is a device that directly convert chemical energy of the fuel into electrical energy (efficiency up to 65%) and heat (efficiency ~30%). Efficiency of SOFC operation depends on its structure and chemical composition of its parts: electrolyte, anode, and cathode. Stabilized zirconia (8YSZ) is the most developed and most commonly used electrolyte material because mostly used material for SOFC electrolyte application and adds to anode and cathode composite to decrease the mismatches of their thermal expansion coefficients with electrolyte. 10Sc1CeSZ is very promising electrolyte material due to its high electrical conductivity comparing to 8YSZ. The matter of this study was to compare electrical properties of two different types of SOFC under the same conditions. To date, two main types SOFC have been studied. They are electrolyte- and anode-supported designs. Electrolyte-supported SOFC: 10Sc1CeSZ – electrolyte, NiO-10Sc1CeSZ - anode, LSCF (La1-xSrхСo1-yFeyO3-δ) - cathode. Anode-supported SOFC: 8YSZ – electrolyte, 8YSZ-NiO – anode, LSCF (La1-xSrхСo1-yFeyO3-δ) – cathode. The low performance of observed is typical for electrolyte-supported cells as higher temperatures are required for higher performance. However, high working temperature is also a rigorous limit for materials of SOFC and decreases fuel cell lifetime and increases fabrication cost. Anode-supported SOFC can be operated at intermediate or low temperature and is preferred over electrolyte-supported design.

Q.4.12
17:30
Authors : P.Frontera, A.Macario, M.Ferraro, S.Santangelo, P.L.Antonucci
Affiliations : Dipartimento di Ingegneria Civile, Energia, Ambiente e Materiali, Università Mediterranea di Reggio Calabria Istituto di Tecnologie Avanzate per l'Energia "Nicola Giordano", Messina INSTM, Consorzio Interuniversitario Scienza e Tecnologia dei Materiali

Resume : The present study concerns the development of anodic tri-metallic catalysts Ni-Mo-Cu supported on Gadolinium Doped Ceria (GDC), suitable to run Solid Oxide Fuel Cells fed by biofuels at intermediate temperature (500--700°C). As known, Ni is a good electro-oxidation catalyst, but still remains the need to find alternative materials because of its excellent cracking activity that leads to its progressive deactivation by gradual coke deposition. Moreover, low working temperatures can cause increased sensitivity to catalyst poisoning, such as sulfur compounds. In order to develop catalysts with high activity and stability, a tri-metallic Ni-Mo-Cu catalyst supported on GDC was thought to be a viable solution, through the synergistic effect of Mo and Cu with Ni. The formulations have been tested in reforming reactions of streams containing up to 100 ppm sulphur (H2S); in particular hydrogen production has been carried out via steam reforming (SR), partial oxidation (POX) and auto-thermal reforming (ATR) processes in temperature range of 500-800°C. For all reactions examined the catalysts are inactive in methane reforming ; instead they are stable and active in the reforming reaction of ethanol. The results confirm that the distribution of the products depends on the reaction temperature and also the amount of carbon deposited on catalysts decreases as reaction temperature increases. A wide physico-chemical characterization of the fresh and spent catalysts has been carried out.

Q.4.13
17:30
Authors : Giuseppe Monforte, Massimiliano Lo Faro, Stefano Trocino, Sabrina Campagna Zignani, Antonino Salvatore Aricò.
Affiliations : CNR-ITAE, Via S. Lucia sopra Contesse 5, 98126 Messina, Italy;

Resume : The technology of solid oxide fuel cells has now reached a proper level of maturity to address problems connected to the remote and distributed generation of electric power. Currently, SOFCs are an appropriate choice for small and medium distributed generation systems (0.5 - 50 kWel). Flexibility in terms of using different kinds of fuel, including those derived from biomasses, without a significant loss in efficiency or an increase in the complexity or cost of the system is a point in favour of SOFCs [1]. Moreover, the choice of liquid fuels is strategic to achieve high energy density as well as allows a reduction of the size, complexity of the system [2]. Typically, air or steam have to be introduced with fuel with systematic control to prevent coking from organics. Accordingly, resistant anode materials towards coke formation under non humidified condition were extensively investigated to simplify the SOFC system [3, 4]. In this study we report the electrochemical and catalytic data for the direct oxidation process of various fuels such as hydrogen, methanol, syngas, glycerol and propane in an SOFC based on a Ni-modified La0.6Sr0.4Fe0.8Co0.2O3 (LSFCO) anode catalyst in the presence of ceria-based electrolytes.

Q.4.14
17:30
Authors : Hee Jin Kim, Ruqia Bibi, Sang-Il Choi*
Affiliations : Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, Daegu 702-701, Korea

Resume : Platinum is generally regarded as the most active catalyst for methanol oxidation reaction (MOR) at the anode in polymer electrolyte membrane fuel cells. However, the extremely rare reserves and high cost of Pt catalyst remain obstacles to commercialize the fuel cell systems. One of the best ways to overcome the drawbacks is to increase the catalytic activity of Pt nanocrystals by controlling their shapes. The shape-control of Pt nanoparticles is usually achieved by utilizing organic surface-capping agents in wet chemistry process. But the capping agents must be removed prior to the catalytic reactions because they block the catalytically active sites and thus disturb the reactions at the surfaces. Here we introduce one-pot synthesis of shape-controlled Pt nanocubes on carbon supports by adjusting the reduction kinetics without adding any capping agents, which enhances the surface exposure of the Pt nanocubes and their catalytic activity over MOR.

Q.4.15
17:30
Authors : A. Moreno-Zuria, L. G. Arriaga, A.U. Chávez-Ramírez
Affiliations : Centro de Investigación y Desarrollo Tecnológico en Electroquímica, 76703 Querétaro, México

Resume : The evolution in the performance of a microfluidic fuel cell stack (μFFC stack) is presented through three different designs operating with HCOOH and O2 as fuel and oxidant respectively. The first design (model A) takes account the conventional operation principle of microfluidic fuel cells involving flat electrodes, on the other hand, the second and third designs using porous electrodes (model B and C respectively). All models employed a window in the cathode side as air intake. Initially, employ flat electrode allowed to achieve high current but low stability. Subsequently, using porous electrode changed the conventional operating principle for membraneless fuel cells but allowed greater stability for long operating times and most importantly, there is flexibility to connect in series or parallel the stack depending on the power requirement. The model A achieved a maximum current and power of 35.96 mA and 7.52 mW respectively with a parallel connection employing a flow of 400 µl/min in each stream. The models B and C used a flow of 150 and 200 µl/min in each stream respectively. The first one reached a maximum current of 3.77 and 6.93 mA with a pick power of 1.69 and 1.63 mW in serial and parallel connection respectively. The second one obtained a maximum current of 35.10 and 5.75 mA with a power of 6.49 and 4.51 mW in serial and parallel connection respectively.

Q.4.16
17:30
Authors : S. Pérez-Rodríguez1, E. Pastor2, M.J. Lázaro1
Affiliations : 1Instituto de Carboquímica (CSIC), Miguel Luesma Castán 4, 50018 Zaragoza, Spain 2Universidad de La Laguna, Dpto de Química-Física, Avda. Astrofísico Francisco Sánchez s/n, 38071 La Laguna (Tenerife), España

Resume : The electrochemical reduction of CO2 has been widely studied on several metals. Additionally, the electrochemical activity of carbon electrodes for CO2 valorization has been also evaluated [1, 2]. However, the influence of the physicochemical properties (surface chemistry, textural properties and structure) on the efficiency of carbons toward CO2 conversion has not been fully analyzed. Thus, further knowledge about the performance of carbon materials for CO2 reduction is necessary. In this work, a study of the impact of oxygen functionalization of the commercial carbon black Vulcan XC-72R (which is the carbon most commonly used in electrochemical applications) on the activity for CO2 reduction is performed. With this aim, the surface chemistry of Vulcan was modified by introducing oxygen surface groups using HNO3 or HNO3-H2SO4. The activity of carbons toward CO2 reduction was analysed by cyclic voltammetry in 0.1 M NaHCO3. Results showed that functionalization treatments led to an inhibition of the activity for hydrogen evolution, which occurs at cathodic potentials by water reduction. On the other hand, a strong influence of the functionalization on the performance for CO2 conversion was observed. All the samples presented a lower faradic current at cathodic potentials in presence of CO2 than those obtained in the electrolyte saturated with Ar. This behavior may be explained by the adsorption of species derived from CO2 reduction (such as COad). However, the formation of adsorbates did not occur for the sample treated with HNO3-H2SO4, probably due to differences in the mix of the surface functional groups as this carbon exhibited a higher contribution of basic groups from temperature programmed desorption analysis. Acknowledgments The authors gratefully acknowledge financial support given by Spanish MINECO (ENE2014-52158-C2-1-R and 2-R). References 1. Christensen, P.A., et al., CO2 reduction at platinum, gold and glassy carbon electrodes in acetonitrile. An in-situ FTIR study. Journal of Electroanalytical Chemistry, 1990. 288(1-2): p. 197-215. 2. Hara, K., A. Kudo, and T. Sakata, Electrochemical CO2 reduction on a glassy carbon electrode under high pressure. Journal of Electroanalytical Chemistry, 1997. 421(1-2): p. 1-4.

Q.4.17
17:30
Authors : Apostolos Enotiadis, Lamprini Boutsika, Isabella Nicotera, Cataldo Simari, Georgia Charalambopoulou and Theodore Steriotis
Affiliations : National Center for Scientific Research “Demokritos”, Ag. Paraskevi Attikis, 15310 Athens, Greece Department of Chemistry and Chemical Technologies, University of Calabria, via P. Bucci, Cubo 14D, 87036 Rende, CS, Italy

Resume : A siliceous layered material has been fabricated through an one-pot sol-gel process and mild thermal aging, anchoring novel functionalities using the aqueous solution of silica source. The hybrid material possesses a high content of sulfonate groups fixed on the solid matrix and shows great stability in water. Its extraordinary characterisics coupled with the easy-scalable method make it a very attractive filler for diverse applications. In this work, sulfonate-rich organosilica layered hybrid (denoted as SSLM) was tested as nanofiller for the preparation of new Nafion-based nanocomposites. The pristine and hybrid membranes were characterized by a combination of techniques, which showed that highly homogeneous exfoliated nanocomposites were obtained. The pulsed field gradient NMR technique was used to measure the water self-diffusion coefficients verifying the exceptional water retention properties of this material. Dynamic mechanical analysis showed that hybrid membranes were much stiffer and could withstand higher temperatures than pure Nafion.

Q.4.18
17:30
Authors : Maria Roca-Ayats1, José M. Luque-Centeno1,2, María Hernández-Caricol1, Weiyang Chen3, Ran Deng3, José Luís G. Fierro1, M. Jesús Lázaro2, King Lun Yeung3, M. Victoria Martínez-Huerta1
Affiliations : 1Institute of Catalysis and Petrochemistry, CSIC. Marie Curie 2. E28049 Madrid, Spain. 2Institute of Carbochemistry, CSIC. Miguel Luesma Castán 4, E50018 Zaragoza, Spain. 3Hong Kong University of Science and Technology. Clear Water Bay, Kowloon, Hong Kong.

Resume : Direct Methanol Fuel Cells (DMFCs) are promising devices for portable and clean energy applications. Methanol has a high density energy for volume unit and is a cheap and secure alternative to hydrogen on fuel cells (FC). There are two reaction involved in DMFC, methanol and CO oxidation and oxygen reduction reaction. Both use platinum as main catalyst which is expensive and have low abundance. Some recent studies have shown that titanium carbonitride is a good alternative to carbon as catalytic support, as it possesses good stability and promotes some reactions, as well [1]. These titanium carbonitrides substrates have been previously used in electrocatalysts for reactions such as oxygen reduction and evolution reactions and carbon monoxide, methanol and ethanol oxidations [1, 2]. However, the main drawback of this material is the low BET surface area, which leads to low mass activities on the catalysts. In order to address this issue, titanium carbonitrides has been modified with graphene and different linkers (Ethylenediamine, Polyethylenimine or Silk Protein). Physicochemical characterization of catalyst was performed by FTIRS, TGA, Raman, XRD, XPS, TEM and ICP-MS. Activity toward ORR, methanol and CO oxidation has been tested. Acknowledgements This work was supported by the Spanish Government under the MINECO project ENE2014-52158-C2-1R (co-funded by FEDER). M.R.A. and J.M.L.C. acknowledges the FPU-2012 program and the FPI-2015 program, respectively, for financial support. References 1. M. Roca-Ayats, G. Garcia, M.A. Peña, M.V. Martínez-Huerta, J. Mater. Chem. A, 2 (44) (2014) 18786. 2. M. Roca-Ayats, E. Herreros, G. García, M.A. Peña, M.V. Martínez-Huerta, Appl. Catal. B: Environ., 183 (2016) 53.

Q.4.19
17:30
Authors : M.J. Nieto-Monge, S. Pérez-Rodriguez, A. Iannaci, B. Mecheri, R Moliner, E. Pastor and M.J. Lázaro
Affiliations : Instituto de Carboquímica, c/ Miguel Luesma Castán nº 4, 50018 Zaragoza, Spain Department of Chemical Science and Technology & NAST Center, University of Rome Tor Vergata, Via della Ricerca Scientifica, 00133 Rome, Italy Instituto de Materiales y Nanotecnología. Universidad de La Laguna. Avda. Astrofísico Francisco Sánchez s/n. 38071 La Laguna, Tenerife, Spain

Resume : Nowadays carbon materials are used as catalyst-support in different energy conversion devices, such as Polymer Electrolyte Membrane Fuel Cells (PEMFCs). Among all kinds of carbon supports, carbon blacks are the most commonly used in the field of electrocatalysis due to their low cost and high performances. However, carbon blacks present an amorphous character, which is prone to undergo electrochemical corrosion, decreasing the durability of PEMFCs. In order to solve this issue, functionalization strategies with different heteroatoms (such as N, S, etc) have been proposed [1] This work deals with the influence of the N functionalization of Vulcan XC-72R (CB) on its tolerance to corrosion. With this aim, CB was treated with HNO3 at 90 ºC during 7 h (CBo) to generate surface oxygenated species on the carbon surface, followed by a treatment with ammonia gas at 400 ºC for 4 h (CBo-N) [2]. Carbons were characterized by different physicochemical techniques, while their electrochemical behavior was studied in acid (0.5 M H2SO4) and basic (0.1 M NaOH) electrolytes by means of cyclic voltammetry. Corrosion experiments were performed cycling the potential from 0 to 1.2 V vs. RHE at 50 mV s-1 for 200 complete cycles for all the samples [3]. Results exhibited that oxygen functionalization of CB led to an increase of the capacitance in both electrolytes, which is associated to an increase of the hydrophilicity and hence, the surface area accessible to aqueous electrolyte, due to the creation of oxygen-containing polar groups during the acid treatment. However, part of these groups was removed during the treatment with NH3 at 400 ºC. Accordingly, the O content obtained by elemental analysis increased in the order: CB < CBo-N < CBo. On the other hand, corrosion tests showed that carbon electrooxidation was favored in basic media. Additionally, CBo showed a lower tolerance to corrosion due to the higher amount of oxygenated species which may act as intermediates in the process. Nevertheless, CBo-N presented the highest stability in both basic and acid media, confirming that N functionalization may decrease the corrosion. Acknowledgments The authors gratefully acknowledge financial support given by Spanish MINECO (ENE2014-52158-C2-1-R and 2-R). Mª Jesús Nieto also acknowledges Ministry of Economy and Competitiveness for their FPI Grant. References [1] R. Nie, X. Bo, C. Luhana, A. Nsabimana, L. Guo. International Journal of Hydrogen Energy 39, 2014 12597-12603. [2] H. Wang, R. Côte´, G. Faubert, D. Guay, J. P. Dodelet. The Journal of Physical Chemistry B, 1999, 103, 2042-2049. [3] A. Zadick, L. Dubau, N. Sergent, G. Berthomé, M. Chatenet. ACS Catalysis 2015, 5, 4819−4824.

Q.4.20
17:30
Authors : Denis Bernsmeier, René Sachse, Michael Bernicke, Ralph Kraehnert
Affiliations : Technische Universität Berlin, Berlin, Germany

Resume : Hydrogen plays a tremendous role in many processes in the chemical industry, e.g. ammonia synthesis. In addition, hydrogen has the highest specific energy density of all chemicals and therefore is a worthwhile medium for storage and transport of energy. The electrocatalytic splitting of water is one possibility to produce hydrogen. Under acidic conditions platinum based electrocatalysts are typically employed. However, Pt is an expensive and scarce element and therefore it needs to be used most efficiently. We present a synthesis strategy which comprises the synthesis of monodisperse colloidal nanoparticles in organic solvent and their successful incorporation into an established synthesis concept for micelle-templated ordered mesoporous carbon (OMC) films. The obtained PtNP/OMC films exhibit well-dispersed small Pt nanoparticles in an electrically conductive open porous matrix. The presentation will discuss the morphology (SEM, TEM) and composition of the colloidal Pt nanoparticles and the PtNP/OMC coatings. Furthermore, the activity in the hydrogen evolution reaction (HER) is presented. The PtNP/OMC catalysts achieve about two times higher HER performance both in fresh and aged state compared to the commercial Pt/Vulcan reference catalysts at similar Pt-loadings. The presentation will discuss the material properties, its advantages and the correlation to HER activity in detail.

Q.4.21
17:30
Authors : S. Frangini(1); C. Felici(1); L. Turchetti(1); M. Liciani(2); L. Della Seta(1); A. Masi(1,3);
Affiliations : (1) ENEA CR Casaccia, Dept. of Energy technologies, Via Anguillarese 301, 00123 Rome , Italy; (2) University of Rome "La Sapienza, Dept. of Chemical, Material and Environmental Engineering, Italy; (3) University of Tuscia, Dept. of Agriculture, Forests, Nature and Energy, Viterbo, Italy;

Resume : Development of high temperature steam electrolysis (HTSE) technologies is expected to play an important role for sustainable production of H2, expecially if combined with the use of renewable electricity. Severe challenges for a successful implementation of HTSE are related to the development of suitable corrosion-resistant materials in the demanding HTSE environments. Although most research focuses on temperatures > 750°C for maximum efficiency, we have recently started the study of a novel steam electrolysis process at temperatures around 500°C, which is optimal to drive the process in integrated Concentrating Solar Power plants. The proposed solar-powered electrolysis process uses a ternary eutectic molten carbonate electrolyte and, differently from the conventional steam electrolysis processes, the gas supplied to the cathode side is a mixture of steam and CO2 . This gas mixture promotes a partial transformation of carbonates into electroactive bicarbonate anions that are the effective species involved in the H2 formation at these temperatures. However, the low O2 activity of the cathode side makes the molten salt extremely corrosive to most common metals. In this context, glass-bonded ceramics have been taken into consideration to develop stable microporous separator and gas diffuser components. We report here an evaluation study on the chemical stability of porous silica glass-ceramic composites in molten carbonates at 500°C, under electrolysis reaction conditions.

Q.4.22
17:30
Authors : Sabrina C. Zignani, Massimiliano Lo Faro, Stefano Trocino, Giuseppe Monforte, Antonino S. Aricò
Affiliations : CNR-ITAE, Via salita Santa Lucia sopra Contesse 5, 98126 Messina, Italy

Resume : The aim of this work is the evaluation of a Fe-air battery cell for application as electric energy storage device. Zhao et al. suggested an architecture similar to a reversible SOFC/SOEC cell combined with an active Fe-electrode placed in the same closed fuel electrode chamber [1]. The operation of such cell consisted in a combination of a reversible SOFC/SOEC cell with the redox cycle of Fe-Fe2O3 and requires a recirculation of H2/H2O. The net electromotive force is given by the Fe-redox couple. Although they achieved good performance, such architecture is affected by cells stacking constraints. In this work we explored the feasibility of a simply architecture consisted of a sandwich based on Fe2O3-CGO as Fe electrode, La0.8Sr0.2Ga0.8Mg0.2O3 (LSGM) or Gd0.1Ce0.9O2 as supporting electrolyte and La0.6Sr0.4Fe0.8Co0.2O3 (LSFCO) as O2 electrode. Such cells had an architecture similar to a SOFC cell. However, such cells did not require any gas recirculation, whereas no internal manifold of gas is expected in a stack of these cells. The cell battery based on CGO showed a significant propensity to the spontaneous discharge due to low electrical stability of the Ce(IV) and due to its large capability for the oxygen storage. On the other hand, LSGM based cell battery showed stable current capacity (0.3 Ah g-1), energy density (0.22 Wh g-1), and voltage efficiency (67%). References [1] X. Zhao, Y. Gong, X. Li, N. Xu, K. Huang, Cyclic Durability of a Solid Oxide Fe-Air Redox Battery Operated at 650°C, J. Electrochem. Soc., 160 (2013) A1716-A1719.

Q.4.23
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SESSION V : Elena Pastor
09:00
Authors : Justo Lobato, Hector Zamora, María Millán, Pablo Cañizares and Manuel A. Rodrigo
Affiliations : Chemical Engineering Department. Av. Camilo Jose Cela n 12. 13004, Ciudad Real, University of Castilla-La Mancha. Spain

Resume : High temperature proton exchange membrane fuel cells (HT-PEMFCs) have certain advantage in the face of common PEMFCs. The use of a high temperature significantly increases the CO tolerance, enhances the oxygen reduction reaction kinetics and reduces the thermal and water management of the system. Platinum on carbon black is commonly used as catalysts in PEM fuel cells. However, the scarcity and high cost of this novel metal and the high corrosion suffered in this carbonaceous support made necessary to look for new materials which decrease the cost without compromising the catalytic activity. In this work, base Pt catalysts were prepared using a novel non carbonaceous support, SiC-TiC. The catalysts were synthesized by an impregnation method using NaBH4 as reducing agent. The catalysts were physical-chemically characterized by ICP-MS, XDR, TPR, SEM and TEM. Besides, cyclic voltammetries in hot phosphoric acid were carried out in a half cell to evaluate the electrochemical resistance in terms of the change of the electrochemical active surface area (EASA). After that, electrodes prepared with Pt based catalyst supported on the novel SiCTiC have been tested in an actual fuel cell of 25 cm2 at 160 ºC. The results are very promising in terms of durability but further work is required to increase the performance. Acknowledgements The authors thank the European Commission as this work was supported by the 7th Framework Programme through the project CISTEM (FCH-JU Grant Agreement Number 325262).

Q.5.1
09:30
Authors : Benoit Guenot [a-b], Thomas Audichon [b], Stève Baranton [b], Claude Lamy [a], Marc Cretin [a], Christophe Coutanceau [b]
Affiliations : [a] Institut Européen des Membranes, Université de Montpellier, ENSCM, CNRS, UMR 5635 Place Eugène Bataillon, CC047, 34095 Montpellier Cedex 5, France ; [b] IC2MP, Université de Poitiers, CNRS, UMR 7285 4 rue Michel Brunet, TSA 51106, 86073 Poitiers Cedex 9, France

Resume : Considering a single electrochemical cell, the main challenge in the development of Unitized Regenerative Fuel Cells based on the PEM technology is the design of bifunctional oxygen electrodes (BOE) able to activate the oxygen reduction reaction (ORR) under fuel cell operation and the oxygen evolution reaction (OER) under water electrolyzer operation. Platinum – a performant ORR catalyst – is usually dispersed on high surface area carbonaceous materials to increase mass efficiency. Nevertheless, carbon cannot withstand the high potential (around 2V vs. RHE) of the oxygen electrode during water electrolysis. Several metal oxides and nitrides such as Sb doped SnO2 or TiN have been studied as carbon-free supports. Although their stability at high potentials is remarkable, their insufficient electronic conductivity impedes the overall performance of the cell. RuO2 performs well as an OER catalyst and exhibits sufficient electronic conductivity. In this approach, we propose to use RuO2 both as catalyst and as durable carbon-free support for Pt nanoparticles. Crystalline RuO2 nanoparticles have been prepared through various hydrothermal treatments with crystal size control. Then Pt nanoparticles were dispersed on the most suitable RuO2 support. After structural and electrochemical characterizations of the obtained bifunctional catalyst, the performances for both OER and ORR have been investigated using a 5 cm² surface area single cell.

Q.5.2
09:45
Authors : M. Oliveira, M. Rebanda, S. Salomé, V. de Zea Bermudez, R. Rego* *rrego@utad.pt
Affiliations : Chemistry Department and CQ-VR, University of Trás-os-Montes e Alto Douro, Quinta de Prados, 5000-801 Vila Real, Portugal

Resume : The performance and durability of low-temperature fuel cells strongly depend on catalyst support materials. One of the most important challenges in the immediate future facing the development of polymer electrolyte fuel cells (PEFCs) is either to stabilize the carbon supports or to find new support materials that improve the durability of catalyst layer and catalyst kinetics [1]. Different types of catalyst support materials have been developed, such as conductive metal oxides, nitrides, carbides, carbon nano (tubes, fibres, dots, horns, coils), graphene, carbon paper, conductive diamonds, among others [1,2]. Eco-friendly ionic liquids (ILs) and deep eutectic solvents (DESs) can be used as promising precursors for functional carbon materials in the field of renewable energy or environmental science [3,4]. DESs have many characteristics of conventional ILs (e.g., low volatility), but exhibit additional advantages, such as low cost, being mainly useful for large-scale synthetic applications. However, relatively cheap ILs, derived from biomass, could also be used for functional carbon synthesis [5]. In the present work, we report for the first time a novel route for the synthesis of Pd supported on a carbon modified-DES and IL (1-ethyl-3-methylimidazolium tetrafluoroborate) using a one-step preparation via a microwave-based strategy in the absence of reducing agents. The preparation of the DES was carried out by heating a mixture of choline chloride and urea at a molar ratio of 1:2 at 70 ºC. The surface morphology and structure of the electrodes were characterized by SEM, HR-TEM/EDX and XRD. ORR activity, kinetics and durability were determined in acid perchloric medium. References [1] A. Rabis, P. Rodriguez, T.J. Schmidt, ACS Catalysis 2 (2012) 864; [2] K. Sasaki, Z. Noda, T. Tsukatsune, K. Kanda, Y. Takabatake, Y. Nagamatsu, T. Daio, S.M. Lyth, A. Hayashi, ECS Transactions 64 (2014) 221; [3] J.P. Paraknowitsch, A. Thomas, Macromolecular Chemistry and Physics 213 (2012) 1132; [4] M.-M. Titirici, R.J. White, N. Brun, V.L. Budarin, D.S. Su, F. del Monte, J.H. Clark, M.J. MacLachlan, Chemical Society Reviews 44 (2015) 250; [5] Z.-L. Xie, D.S. Su, European Journal of Inorganic Chemistry 7 (2015) 1137.

Q.5.3
10:00
Authors : Paritosh Mohanta and Ludwig Jörissen
Affiliations : Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg (ZSW), Helmholtzstraße 8, 89081 Ulm (Germany)

Resume : The instability of the carbon based support materials is one of the major causes of Polymer Electrolyte Membrane Fuel Cells (PEMFC) performance degradation. We investigated the performance stability of Pt electro-catalysts supported on a typical carbon black, a stabilized carbon support and a non- carbon. A robust synthesis method of Pt nanoparticles of <5nm particle size has been developed by modifying the well-known polyol method. With the synthesis process chosen, Pt nano-particles were successfully deposited on both carbon and the non-carbon supports. Electrochemical surface area by CV, Oxygen reduction reaction activity by RDE and degradation via potential cycling were measured for all catalysts. Finally, the catalysts were processed to MEAs and subject to single cell performance tests. The stable carbon supports showed improved corrosion resistance as compared to the traditional carbon black support under accelerated stress test (AST) condition. The membrane electrode assembly (MEA) performance test results of the stable carbon supported catalysts are also comparable with the carbon black supported catalyst. We developed a non-carbon (Sb doped SnO2) support material of reasonable electrical conductivity (10 times lower than Carbon black) and surface area of 50m2/g which showed comparatively low loss of electrochemical active surface as the stable carbon supports upon potential cycling. The MEA performance of Sb doped SnO2 supported catalyst is currently under investigation.

Q.5.5
10:30 Coffe Break    
 
SESSION VI : Enrico Traversa
11:00
Authors : Barbara Mecheri, Alessandra D'Epifanio, and Silvia Licoccia
Affiliations : Department of Chemical Science and Technologies, University of Rome Tor Vergata

Resume : The current need for new solutions for waste management and clean energy production can find a concrete answer in the technology of microbial fuel cells (MFCs). MFCs are bio-electrochemical systems which allow producing electrical energy, using wastewater as fuel, eliminating at the same time some of the problems linked to their disposal . Current limitations and open problems related to MFC technology are the high costs associated to materials, cell configurations not yet suitable for scaling-up, and the complexity of wastewater. To address these issues, the research activity of our group is focused on the identification of innovative and cost-effective materials and components to fabricate lab-scale MFC prototypes, fed with wastewaters of different nature. Subject of this presentation will be an overview of our recent activity in the field of MFCs. Special emphasis will be given to the development of low cost and effective catalysts for the oxygen reduction reaction occurring at the cathode. The combination of carbon supports with electronically conducting polymers, non noble metals, ceramic oxides, and enzymes was investigated to boost catalytic activity, while reducing the adsorption of contaminant species. The use of food waste and agro-industrial wastewater as fuel of MFCs will be proposed, highlighting opportunities and constraints in terms of energy production as well as efficiency of wastewater treatment.

Q.6.1
11:30
Authors : Ricardo A. Escalona-Villalpando, Shelley D. Minteer, L. G. Arriaga, J. Ledesma-García.
Affiliations : Ricardo A. Escalona-Villalpando; L. G. Arriaga. Centro de Investigación y Desarrollo Tecnológico en Electroquímica, 76703, Querétaro, México. Shelley D. Minteer. Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, UT 84112, United States. J. Ledesma-García. División de Investigación y Posgrado, Facultad de Ingeniería, Universidad Autónoma de Querétaro, 76010, Santiago de Querétaro, México

Resume : The use of lactate as fuel is very attractive due to their high energy density of 507 Wh/L in the oxidation for a single enzyme and complete oxidation of 3041 Wh/L. In this work, we evaluated a lactate biofuel cell (BFC) using like bioanode lactate oxidase with redox polymer dimethylferrocene-modified linear polyethyleneimine and two different cathodes enzymatic based on laccase (BFC-1) and bilirubin oxidase (BFC-2) coupled to MWCNT modified with anthracene and an abiotic catalyst Pt/C (BFC-3) estimated on sweat direct (lactate concentrations of 5 - 70 mM). The result shown a cell voltage (OCV) of 0.6 V (BFC-1), 0.56 V (BFC-2) and 0.36 V (BFC-3), with maximum of density current of 78 µA cm-2, 47 µA cm-2 and 4.9 µA cm-2 respectively with good stability. In conclusion, the performances of the BFCs evaluates would be apply for devices of low current and self-powered sensor as a supplemental power supply.

Q.6.2
11:45
Authors : Thi Xuan Huong Le, Mikhael Bechelany, Adriana Both Engel, Marc Cretin, Sophie Tingry
Affiliations : IEM (Institut Europeen des Membranes), UMR 5635 (CNRS-ENSCM-UM), Universite de Montpellier, Place E. Bataillon, F- 34095, Montpellier, France

Resume : In this study, homogeneously dispersed gold particles onto carbon felt were fabricated by electrodeposition method followed by a thermal treatment at 1000 °C under nitrogen. The thermal treatment induced the dewetting of gold and the formation of well-crystallized gold particles that exhibited large surface area. The structural properties of the resulted Au@CF material were evaluated by SEM, XRD and TGA. We studied the electrocatalytic properties of this new gold material toward the abiotic glucose oxidation in alkaline medium and the enzymatic dioxygen electroreduction by the enzyme bilirubin oxidase. Finally, we showed the potentiality of the resulting Au@CF material to construct a 3-dimensional glucose hybrid biofuel cell by assemblying an abiotic anode with an enzymatic cathode. The system exhibited high electrochemical performance, by taking account of the projected surface area, with an open circuit voltage of 0.71 V and a maximum power density of 310 µW cm-2 at 352 mV, in spite of a low gold loading (0.2 wt%). The advance presented in this work is the efficiency of the synthesis technique to get a new free-standing material for electrocatalysis with macropores for diffusion transport and gold particles with high reactive surface area for electron transfer.

Q.6.3
12:00
Authors : S.LOUKI* , N. TOUACH*, A. BENZAOAUK*, F. HERNANDEZ-FERNANDEZ**, V.M. ORTIZ-MARTINEZ**, M.J. SALAR-GARCIA**, M. EL MAHI*, N. LABJAR* and E. M. LOTFI*
Affiliations : * Laboratory of Mechanics, Processes and Industrial Processes, ENSET, Mohammed V University of Rabat, Morocco ** School of Chemical and Environmental Engineering, Polytechnic University of Cartagena, Campus Muralla Del Mar Murcia, Spain

Resume : The microbial fuel cell is a device which allows both to generate bioelectricity and to treat wastewater [1]. The performance of this system is affected by several parameters, in particular the cathode material [2]. In this perspective, two cathodes, synthetised and caracterised, of non-stoichiometric ferroelectric material of formula Li0,95Ta0,57Nb0,38Cu0,15O3, were prepared according to two heat treatments modes (slow cooling-S- and rapid cooling -R-). The synthesized phases were characterized by XRD, TEM, specific surface area, laser granulometry (PSD) and density measurements. These phases have the principales characteristics as Curie temperatures,1215 and 1196°C and specific surface area 0.572 and 0.801 m2 /g for S and R phases respectivelty. These materials were tested as photocathodes in a microbial fuel cells single chamber for the treatment of wastewater. The performance of these photocatalysts in terms of electricity generation and wastewater treatment were evaluated by power density and rate of COD removal in the presence of a light source. For the samples S and R the values of the maximum power densities are 22.82 mW/m3 and 213.38 mW/m3, the COD removal are 74 % and 80% respectively. We noted the phases prepared by rapid cooling -R- are more successful in terms of powers generated and of the efficiency of the wastewater treatment improves significantly the photocatalytic activity of the material. Key words: Tantalo-niobate, phase, photocatalyst, slow cooling,rapid cooling,MFC, COD [1]. Liu, H. and B.E. Logan, Electricity generation using an air-cathode single chamber microbial fuel cell in the presence and absence of a proton exchange membrane. Environmental science & technology, 2004. 38(14): p. 4040-4046. [2]. A. Lu, Y. Li, S. Jin, H. Ding, C. Zeng, X. Wang, C. Wang, Microbial fuel cell equipped with a photocatalytic rutile-coated cathode, Energy & Fuels, 24 (2009) 1184-1190.

Q.6.4
12:15
Authors : N. Touach*, A. Benzaouak*, V.M. Ortiz-Martínez**, M.J. Salar-García**, F. Hernández-Fernández**, A.P de los Ríos***, M. El Mahi* and E.M.Lotfi *
Affiliations : *Laboratory of Mechanics, Processes and Industrial Process, Team Chemical Sciences, ENSET, Mohammed V University of Rabat, Morocco **School of Chemical and Environmental Engineering, Polytechnic University of Cartagena, Campus Muralla Del Mar Murcia, Spain. +34 968325551. ***University of Murcia, Chemical Engineering Department, Campus de Espinardo, E-30071 Murcia. +34 868 88 9112

Resume : In this work, the experiments are conducted by cathodes composite based ferroelectric LiNbO3 catalyst and carbon cloth support conductor. It has been investigated in terms of power output in single-chamber MFCs, in the absence and in the presence of UV-Vis light. This material catalyst was synthesized, identified and characterized by XRD, MET and PSD techniques. Maximum values of open circuit potential (OCP) and power densities were observed in the presence of UV-Vis are 400 mV and 115,14 mW.m-3, respectively. This cathode configuration also offered the maximum chemical oxygen demand (COD) removal with a value of 76 % after 72 h of MFC operation using wastewater as fuel. Finally, the analysis of the removal of heavy metal from wastewater (63Cu, 66Zn, 111Cd,52Cr and 56Fe) shows removal efficiencies within the interval 60-85% for most of the metals studied in the case of irradiated LiNbO3 configuration.

Q.6.5
12:30 Lunch Break    
 
SESSION VII : Vincenzo Antonucci
14:00
Authors : Elena Pastor
Affiliations : Departamento de Química - Instituto de Materiales y Nanotecnología. Universidad de La Laguna. La Laguna, Tenerife, España.

Resume : The development of alkaline polymeric membranes has allowed that alkaline electrolysis becomes an attractive alternative because it permits the use in these devices of electrocatalysts with non-noble metals, such as Ni and Mo. These materials are stable in alkaline medium, have good resistance to corrosion and exhibit high activity not only in the reaction of hydrogen evolution (HER), but also the oxidation of alcohols when combined with low content of Pt or Pd, so they can be used both in electrolyzers and polymer electrolyte membrane (PEM) fuel cells. In this work Ni nanodisks supported on reduced graphene oxide (RGO) were prepared and modified with Mo and Pt for the study in alkaline media of the HER and alcohol oxidation reactions (AOR), respectively. Structure of synthesized materials was characterized by X-ray and microscopy techniques. Differential electrochemical mass spectrometry showed a negative shift of 150 mV towards negative potentials for the onset of the HER at Ni-Mo materials with respect to pure Ni and Mo. On the other hand, Ni@Pt/RGO catalysts were obtained by galvanic replacement developing a core-shell structure. The onset for AOR at these materials was established at more negative potentials for the catalysts with lower Pt content, which also presented the highest mass current densities. The high activities achieved with modified Ni/RGO nanodisks in alkaline media make then good candidates to be used as catalysts for PEM devices using alkaline membranes. Acknowledgments Financial support given by Spanish MINECO (ENE2014-52158-C2-1-R and 2-R, FEDER) and Fundación Cajacanarias (BIOGRAF project) was gratefully acknowledged.

Q.7.1
14:30
Authors : Dr. Ujjal K. Gautam
Affiliations : Assistant Professor, Department of Chemical Sciences, Indian Institute of Science Education Research, Mohali, Sector 81, SAS Nagar, Punjab 140306

Resume : Pt based nanostructures are the widely sought after metal-based nanomaterials for various catalytic applications including renewable energy harvesting, which, due to growing energy demand, is fast emerging as a key research area. Despite extensive investigations, certain Pt nanocrystals with excellent potential performance have remained elusive, giving rise to important research challenges. This talk will illustrate our recent successes in realizing such nanostructures that leads to enhanced energy harvesting. Earlier we established that by generating a secondary amine in-situ during their synthesis, sub 10 nm Pt nanotetrahedra (NTds with (111) surfaces that are thermodynamically unfavourable) exhibiting one of the highest electrochemical efficiencies towards fuel reduction can be obtained. Subsequently, we demonstrated a mechanochemical unzipping process of a nanotube structure to yield robust free-standing ~26 nm thick Pt nanosheets, a rare morphology for metals. Therein, shear forces (~2 N) and shear stress (~24000 Pa) generated by stirring in a solution was utilized to mechanochemically zip open an 1D nanostructure to form a nanosheet. Nanocrystals are crystallographically connected to each-other within the nanosheets and therefore can be used for electrochemical applications without using conducting supports. This alleviates the problems associated with catalyst masking by the catalyst-support and leads to high mass-activity in fuel cell reactions. Besides, a ‘support-less’ strategy involving Pt nanowire membrane recently developed by us will be discussed. Finally, a novel approach that uses carbon, a usual support material, as multifunctional material for hybrid energy storage shall be illustrated. References 1. “Mechanochemical Synthesis of Free-Standing Platinum Nanosheets and Their Electrocatalytic Properties”, M. Chhetri , M. Rana , B. Loukya , P. K. Patil , R. Datta , U. K. Gautam, Adv. Mater., 2015, 27, 4430. 2. “High-yield Synthesis of Sub-10 nm Pt Nanotetrahedra with Bare (111) Facets for Efficient Electrocatalytic Applications”, M. Rana, M. Chhetri, B. Loukya, P. K. Patil, R. Datta, U. K. Gautam, ACS Appl. Mater. Interfaces, 2015, 7, 4998. 3. Pd–Pt Alloys Nanowires as Support-less Electrocatalyst With High Synergistic Enhancement in Efficiency for Methanol Oxidation in Acidic Medium, M Rana, P. K. Patil, M. Chhetri, K. Dileep, R. Datta, U. K. Gautam, J. Colloid Interface Sci., 2016, 463, 99. 4. N-and S-doped High Surface Area Carbon Derived from Soya Chunks as Scalable and Efficient Electrocatalysts for Oxygen Reduction, M. Rana, G. Arora, U. K. Gautam, Sci Tech. Adv. Mater., 2015, 16, 014803.

Q.7.2
15:00
Authors : Shangfeng Du1*, Yaxiang Lu1,2, Kaijie Lin and Hanshan Dong3
Affiliations : 1* School of Chemical Engineering, University of Birmingham, UK 2 Department of Chemical and Process Engineering, University of Surrey, UK 3 School of Metallurgy and Materials, University of Birmingham, UK

Resume : Fuel cell is a clean power generator with high energy efficiency and low carbon emission. Benefiting from low operation temperature and high speed start-up and shutdown, polymer electrolyte membrane fuel cells (PEMFCs) have stepped in the demonstration stage. Over the past decades, the study of nanotechnology has brought in tremendous progress to PEMFC development, in particular on understanding catalytic mechanisms of fuel cell reactions on catalyst surfaces, and many new catalyst approaches have been reported. However, the only considered catalyst for commercialization is still the conventional Pt/C catalysts. This presentation will highlight the increasing concern of the gap between pure material research and fuel cell devices, and review the research activities undertaken in Birmingham by combing green chemical synthesis [1-3] and new plasma techniques [4] to create advanced catalyst electrodes for high performance PEMFCs. References 1. S. Du. J. Power Sources 195, 289-292 (2010) 2. Y. Lu, et. al, Appl. Catal. B 164, 389-395 (2012) 3. Y. Lu, et. al, Appl. Catal. B 187, 108-114 (2016) 4. S. Du, et. al, Sci. Rep. 4, 6439 (2014)

Q.7.3
15:30 Coffe Break    
 
SESSION VIII : Elena Pastor
16:00
Authors : C.M.Rangel1*, V.R. Fernandes1, O. Furtado1, J. Rodrigues2
Affiliations : (1) Laboratório Nacional de Energia e Geologia, Paço do Lumiar, 22, 1649-038 Lisboa, Portugal, (2) GSyF, Pol. Ind. Alto do Ameal, Pavilhão C-13, 2565-641 Torres Vedras, Portugal

Resume : Hydrogen produced by water electrolysis is considered as the best energy carrier to adjust the balance between the generation of power source by renewable primary energy and energy demand for end-use. In assisted water electrolysis using carbon as anodic material (graphite, activated carbon and coal), the real operating voltage and the actual energy consumption would be lower than for conventional water electrolysis, with apparent reduction of the cost for hydrogen production. In this work, the low temperature and low pressure electrochemical gasification of graphite in alkaline solutions is explored, taking into account that above the thermodynamic potential for oxygen evolution the faradaic overall current might have a significant contribution from carbon oxidation reactions and seeking the production of synthetic liquid fuels via syngas. In a first stage, laboratory studies were conducted in an undivided planar cell with graphite electrodes with 25 cm2. Cyclic voltammetry and polarization curves were instrumental to establish optimum operational conditions for adequate molar gases fraction for the production of syngas. Gaseous product analysis was carried out using gas chromatography. A 45W prototype using a 5 cell stack with 150 cm2 was built allowing electrolyte recirculation, temperature control up to 80ºC and pressure control up to 1 bar with excellent results in both alkaline and acid media. A 1 kW prototype has been built for working with alkaline media with the molar fraction of gases is in excellent agreement with the found in the laboratory prototype for similar operating conditions. Integration with renewables for powering electrolysis and also with a reactor for the production of methanol is expected. Results and the technological implications of the obtained advances are discussed. KEYWORDS: Hydrogen, Carbon monoxide, Carbon dioxide; Electrochemical gasification; Graphite, Electrolysis. ACKOWLEDGEMENTS This work is co-financed by COMPETE, Portugal under project nº 38940. REFERENCES [1] J. Rodrigues, Portuguese Patent 106779 T: Obtenção de gás de síntese por eletrólise alcalina da água, 2013.02.13

Q.8.1
16:30
Authors : Dehua Xiong, Xiaoguang Wang, Wei Li and Lifeng Liu,*
Affiliations : International Iberian Nanotechnology Laboratory, Av. Mestre Jose Veiga, 4715-330 Braga, Portugal

Resume : Since 2013, transition metal phosphides (TMPs) have emerged as a new class of catalysts for the hydrogen evolution reaction (HER), whose catalytic performance was reported to favorably compare to that of Pt and outperform that of many metal sulfides, selenides, and carbides. Among various TMPs investigated by far, iron phosphide is particularly attractive because iron is the cheapest and most plentiful transition metal in the earth’s crust (the primary source of metal ores); moreover, it has low toxicity and negligible environmental impact. Up to now, many iron phosphide nano-catalysts have been reported for use to catalyze the HER, but its catalytic performance toward the oxygen evolution reaction (OER) has been rarely explored, even if TMPs were recently reported to be active OER catalysts as well. In this work, we report the fabrication of FeP nanorods (NRs) and their electrocatalytic performance toward the OER. The synthesis of FeP NRs was accomplished by a facile hydrothermal process modified according to a previous report, where iron oxyhydroxide (FeOOH) NRs were first obtained upon cooking 0.15 M FeCl3·6H2O and 1 M NaNO3 solution in a Teflon-line steel autoclave reactor at 100 °C for 24 h; this was followed by doctor-blade of FeOOH NRs on carbon fiber paper (CP) current collectors and subsequent phosphorization treatment in P vapor at 500 °C for 0.5 h. Phosphorization treatment further significantly enhances the OER activity, the CP@FeP exhibits higher current density and a more negative onset potential (1.52 V vs. RHE) than CP@FeOOH (1.65 V vs. RHE). We find that FeP NRs supported on carbon fiber paper (CP) current collectors exhibit OER activity (ηon = 290 mV, η10 = 350 mV, Tafel slope = 64 mV dec-1) superior to that of many transition metal based OER catalysts reported in the literature, and they also show excellent long-term stability (48 h) for the OER.

Q.8.2
16:45
Authors : G. Brunaccini 1, F. Sergi 1, D. Aloisio 1, M. Ferraro 1, M. Blesznowski 2, J. Kupecki 2, K. Motylinski 2, and V. Antonucci 1
Affiliations : 1) Institute of Advanced Energy Technologies “Nicola Giordano” National Research Council of Italy, Messina, Italy 2) Thermal Processes Department, Institute of Power Engineering, Warsaw, Poland

Resume : Novel telecommunications services must be supported by a widespread infrastructure and technological advances. Radio Base Stations (RBSs) belong to the mobile services infrastructure and, since they are connected to the grid, they represent a relevant source of costs and energy consumption to ICT operators. For this reason, ICT operators are working on internal power production in RBSs, instead of being passive loads to the electrical grid. In the framework of the ONSITE project (financed by FCH JU, Grant No. 325325, www.onsite-project.eu), which deals with a hybrid (fuel cell and batteries) RBS supply system, a modeling activity was carried out to optimize the system operations. The developed algorithms separately implement a SOFC system and a high temperature (SNC) battery for design purpose and collect them in a unique model for devices interaction (i.e. power production, storage, and control). Moreover, a CFD battery model was developed to analyze the heat transfer while the SOFC stack generates excessive heat during operation and outlet hot gases can be effectively used. Since the SNC batteries need heat during charging process (to maintain their operating temperature) and, conversely, the reactions are exothermic in discharge mode, the described approach aims at combining SNC batteries with micro-CHP unit to optimize the energy flows. The implementation required several alternative designs and variant analysis to secure proper operation of battery and power generation unit.

Q.8.3
17:00
Authors : Felicity Taylor, John Buckeridge, C. Richard A. Catlow
Affiliations : University College London, Kathleen Lonsdale Materials Chemistry, Department of Chemistry, 20 Gordon Street, London, WC1H 0AJ, UK

Resume : Solid oxide fuel cells (SOFCs) are a strong candidate for zero-emission electricity generation. However, the high temperatures necessary for operation lead to long start up times and short lifetimes. Decreasing this temperature leads to a decreased rate in the oxygen reduction reaction at the cathode site, leading to a need for new cathode materials active at reduced temperatures. Doped perovskite materials, such as LSCF, show great promise as IT-SOFC cathodes. However, optimisation of these materials can be difficult due to the large variation in stoichiometry that is possible. Here we present a detailed study of intrinsic point defects, substitutional defects and oxide ion migration in LaFeO3, a parent compound of LSCF. With an understanding of the chemistry of the base material it is possible to predict the effect of doping and therefore to be able to optimise this material for its purpose. Both molecular mechanical and density functional theory calculations have been employed in this work, with the majority of intrinsic defects investigated having high formation energies with the exception of O2- vacancies. A range of divalent dopants have been investigated for both the A- and B-site and the most appropriate for each will be discussed, along with their affect on the electronic properties of the material. Oxide ion conduction calculations revealed activation energies of 0.58 and 0.66 eV, agreeing well with the reported experimental value 0.77 eV.

Q.8.4
17:15
Authors : M Asteazaran, G Cespedes, AR Bonesi, A M Castro Luna
Affiliations : Centro de Investigación y Desarrollo en Ciencia y Tecnología de Materiales (CITEMA), Facultad Regional La Plata, UTN, La Plata, Argentina; Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, UNLP-CONICET, La Plata, Argentina

Resume : Direct methanol fuel cells (DMFCs) can provide energy as long as the fuel is feeding the cell. Unfortunately, DMFC undergoes slow kinetics for alcohol oxidation at the anode and at the cathode both the oxygen reduction reaction (ORR) and the methanol oxidation reaction (MOR) occur simultaneously. To lessen the alcohol crossover issue, some binary and ternary Pt base catalyst with high activity for the ORR and low activity for the MOR has been synthesized. We have found that home synthesized catalyst PtCoRu/C can be active enough for ORR and almost no active for MOR, whereas PtCo/C is active for ORR and MOR. The electrochemical behaviour of the catalysts as prospective anode is analysed and compared with homemade PtRu/C. Thus, PtRu/C behaves as the best catalyst for MOR, and its Nyquist plot shows the smallest charge transfer resistance. The PtCo/C catalyst, which is very active for ORR and MOR at high potentials, behaves as a poor catalyst for MOR at low potentials. Finally, PtCoRu/C which has shown good ORR behaviour and also proves to be resistant to methanol oxidation shows the highest charge transfer resistance and consequently the poorest activity for MOR. EIS results have been modelled according a combined electrical circuit which represent the reaction mechanism of methanol oxidation. The chance of having Pt and Ru in the catalysts composition is not enough to ensure a higher catalytic activity for MOR.

Q.8.6
 
POSTER SESSION II : Vincenzo Baglio
17:30
Authors : Giacoppo G.* 1), Barbera O. 1), Briguglio N. 1), Cipitì F. 1), Ferraro M. 1), Brunaccini G. 1), E. Erdle 2) and Antonucci V.1)
Affiliations : 1)CNR – ITAE – Istitute for Advanced Energy Technologies “Nicola Giordano” Salita S. Lucia sopra Contesse 5, Messina 98126, Italy 2)EFCECO, Germany

Resume : In this paper, the integration of small SOFC commercial system into the fuselage of a mini Unmanned Aerial Vehicles (UAVs) is carried out from an experimental and computational point of view. As a design constrain, the SOFC generator has to be installed inside the UAV fuselage, with the lowest possible offset (about 20 mm all around the generator) to reduce the volume and mass of the UAV. SOFC systems operate at high temperature in the range of 800 – 1000 °C and even whether a good insulation of the system is designed, the external temperature is always about few hundred Celsius degrees. Due to high external surface temperature, malfunctioning of the electronics devices connected to the generator and hot spots on the fuselage shell can occur. For this reason, it is important to ensure a proper ventilation of the air volume inside the UAV fuselage. To deal with these issues, experimental and Computational Fluid Dynamic studies were carried out to evaluate the temperature distribution inside the UAV fuselage. Different air intake configurations and design are investigated and advises concerning a correct SOFC system integration inside the UAV fuselage are also provided.

Q.8.7
17:30
Authors : G.M. Kaleva, E.D. Politova, I.P. Sukhareva, A.V. Mosunov, and N.V. Sadovskaya
Affiliations : L.Ya. Karpov Institute of Physical Chemistry, Obukha s.-st., 3, 105064, Moscow

Resume : Synthesis, structure, microstructure and electroconductivity of modified lanthanum gallate ceramics as perspective electrolytes for high temperature solid oxide fuel cells G.M. Kaleva, E.D. Politova, I.P. Sukhareva, A.V. Mosunov, and N.V. Sadovskaya L.Ya. Karpov Institute of Physical Chemistry, Obukha s.-st., 3, 105064, Moscow e-mail:politova@cc.nifhi.ac.ru Aliovalent substituted lanthanum gallate La0.9Sr0.1Ga0.8Mg0.2O3-y (LSGM) is being considered among the most perspective electrolyte materials for the intermediate temperatures solid oxide fuel cells because of its high ionic conductivity in the wide range of the partial pressure of oxygen (1 – 10-22 atm.) and insignificant electronic conductivity. Previously, we have studied the characteristics of the crystal structure, electroconductive and magnetic properties of LSGM ceramics with a perovskite structure by substituting of gallium cations by iron cations. Single phase samples with the orthorhombic structure were synthesized in the entire region of iron concentrations. Antiferromagnetic ordering at temperatures below 500 K was revealed for the composition (La0.9Sr0.1)(Fe0.8Mg0.2)O3-y. In this work ceramic samples in the system (La0.8Sr0.2){[Ga0.8-x(Si0.5Mg0.5)x]Mg0.2}O3-d (x=0 ÷ 0.8) were prepared by the solid state reaction method. The phase formation, crystal structure, microstructure and electroconductivity were investigated using the X-ray Diffraction, Scanning Electron Microscopy and Dielectric Spectroscopy methods. According to the X-ray diffraction data, perovskite structure phase was formed in the samples with x = 0 ÷ 0.6. These compounds are characterized by the orthorhombic structure (space group Pbnm). Fragments of diffraction patterns of the samples demonstrate a consistent shift of the diffraction peaks to smaller angles, indicating to the slight increase in unit cell parameters as a result of substitution of Ga cations by Si and Mg cations. It was found that the silicon-containing samples are characterized by a homogeneous microstructure of square shape with grain sizes (10x10) mkm. The temperature dependences of the total electroconductivity of ceramic samples confirmed their high values at temperatures near 1000 K. This work was supported by the Russian Foundation for Basic Research, project no. 16-03-00581.

Q.8.8
17:30
Authors : Mario Branchi, Diana De Porcellinis, B arbara Mecheri, Silvia Licoccia, and Alessandra D’Epifanio
Affiliations : Department of Chemical Science and Technologies, University of Rome Tor Vergata

Resume : Vanadium Redox Flow Batteries (VRFB) are electrochemical devices able to store energy using vanadium species dissolved in solution as electrolytes. VRFB are a promising technology for sustainable and environmental friendly large-scale energy storage. However, major challenges such as low energy density, low stability, and high cost limit further development of this technology. The polymer membrane used as separator is indeed a critical component for VRFB development. Perfluorosulfonic polymers, such as Nafion, are commonly used in VRFBs due to their high proton conductivity and good chemical and thermal stability but suffer from high cost and important vanadium ion crossover. Our approach to reduce costs and vanadium-ion crossover was based on the use of composite membranes based on sulfonated poly ether ether ketone modified with the addition of different loading of nanometric titanium oxide, either as a pure species or functionalized with surface acidic groups. The homogeneity of composite membranes was enhanced by using an air-spraying deposition technique and results were compared with those obtained with conventional solvent casting methods. Vanadium ion permeability through the membranes was evaluated by using a static H-type glass cell, measuring vanadium ion concentration by UV-Vis. Proton conductivity of membranes was measured by in situ-electrochemical impedance spectroscopy. Coulombic and energy efficiencies of the cell were studied by galvanostatic charge-discharge cycles. The overall performance of was further analyzed by polarization curve at different state of charge. Early insights on the understanding of battery capacity loss in long-term cycling tests is also reported in this work.

Q.8.9
17:30
Authors : A. Dumitru, S. Vulpe, A. Radu , M. Temelie, A. Csolti and B. Bita
Affiliations : Faculty of Physics, University of Bucharest, Magurele, ROMANIA

Resume : In the recent years, the nitrogen-containing carbon nanostructures (NCNS) have received increasing attention especially because of their applicability in the fabrication of new catalysts, electrocatalysts, and electrode material for supercapacitors. The aim of this study is the investigation of electrocatalytic activity toward oxygen reduction reaction of NCNS. The carbonization of polyaniline nanostructures as nitrogen containing precursors was used for the preparation of NCNS. Polyaniline nanostructures were synthesized using three different template free polymerization methods. In the present work we compared the efficiency of these materials for oxygen reduction reaction (ORR) in alkaline media. The electrochemical behavior was correlated with data obtained from X-ray Photoelectron Spectroscopy, Scanning Electron Microscopy and Raman Spectroscopy. Acknowledgments This work is supported by a grant of the Romanian National Authority for Scientific Research and Innovation, CNCS – UEFISCDI, project number PN-II-RU-TE-2014-4-0221.

Q.8.10
17:30
Authors : C. D’Urso, G. Bonura, V. Baglio, A.S. Aricò
Affiliations : CNR-ITAE, Istituto di Tecnologie Avanzate per l'Energia "Nicola Giordano" Via S. Lucia sopra Contesse, 5 - 98126 Messina (ITALY)

Resume : This work focuses on the synthesis of Tantalum (Ta) modified TiO2 mixed oxides and their structural and surface properties characterization using XRD, XPS, BET and H2-TPR techniques. Tantalum (Ta) modified TiO2 samples were synthesized using a sol-gel procedure and evaluated for potential application as electrocatalysts supports. The Tantalum (Ta) modified TiO2 mixed oxides showed unimodal nanoporous structure with pore sizes ranging from 3 to 5 nm. Concomitantly with their higher surface area and pore volume, the mixed oxides were nanocrystalline and significantly smaller than Ti and Ta single oxides prepared by the same method (7 to 8 nm). A dominant anatase phase was detected by XRD at low calcination temperature, while the crystallographic structure become ruthile when the sample was treated at 850°C. Lattice parameters were changed by incorporating Ta into TiO2. H2-TPR revealed that the oxidation state of surface cations decreased, and oxygen deficiency of the surface was significantly enhanced by introducing Ta into TiO2. The structural and surface modification by introducing Ta into TiO2 increased the reducibility of mixed oxides in H2-TPR. The present study clearly established that the structural (crystal phase, crystal size, nanoporosity, pore size) and surface properties (reducibility, oxygen deficiency, acidity, oxidation activity) of the Tantalum (Ta) modified TiO2 mixed oxides can be tailored by modifying the sol gel procedure and the thermal treatment.

Q.8.11
17:30
Authors : Susanna Maisano, Giovanni Zafarana, Francesco Urbani, Vitaliano Chiodo
Affiliations : Susanna Maisano Institute CNR-ITAE; Giovanni Zafarana Institute CNR-ITAE; Francesco Urbani Institute CNR-ITAE; Vitaliano Chiodo Institute CNR-ITAE;

Resume : In the last decade the worldwide interest on renewable energies researches of bio-fuels have been intensified to meet the increasing fuel demand and secure local energy. The attention was addressed toward the employment of third generation biofuels derived from algae that are a cheaper feedstock for chemicals and biofuels production. The pyrolysis process is considered a good and economical process and also shows higher efficiency than other process for conversion of algae into bio-fuels. Moreover, bio-oils can be upgraded in-situ by catalytic cracking to reduce its high acidity and oxygen content and increase the low heating value. For this reason, Ni based and Ni-Ceria catalysts have been utilized in pyrolysis processes mainly for their low cost and to promote deoxygenation reactions. Although, many papers are present in literature on catalytic pyrolysis, the researches on effect of catalysts to the pyrolysis of sea plants are really scarce. The aim of this work was to evaluate about the feasibility of the process to produce high quality bio-oil from a Mediterranean sea plant. In particular, the effects of pyrolysis parameters such as temperature and different prepared Ni based catalysts on product yields were investigated. The amount of char, gas and oil was determined and moreover bio-oil was studied in terms of oxygen and organic compounds content. The results showed that both temperature and catalyst had significant effects on conversion into the products.

Q.8.12
17:30
Authors : Barbera Orazio, Stassi Alessandro, Sebastian David, Giacoppo Giosuè, D’Urso Claudia, Baglio Vincenzo, Aricò Antonino Salvatore
Affiliations : CNR – ITAE, National Research Council of Italy, Institute for Advanced Energy technologies, Via Salita S. Lucia sopra Contesse, 5 98126 Messina, Italy

Resume : Direct Methanol Fuel Cells (DMFCs) have received worldwide attention because of several intrinsic advantages, such as simplicity of operation, high theoretical energy density and easy refueling. Being Methanol a liquid fuel, DMFCs are simpler in construction than hydrogen fed fuel cells, and do not need pressurised hydrogen gas storage, delivery or processing. Additional simplification in DMFCs includes passive operation with air-breathing operation for low power applications. In recent years, technology developments have promoted interest around DMFC applications in small portable power devices, such as notebook computers, power tools and cellular phones, which need power sources with increasingly high energy density and easy recharging. In this work, an innovative DMFC fuel cell ministack, designed for operation at ambient pressure and temperature, under air breathing and using methanol diffusion by natural convection, has been evaluated in terms of performance, durability and reliability. The architecture of the ministack has been conceived as planar and modular; with each pair of current collectors, and clamping plates combined on a single component made with two PCBs. Four different geometries of cathode feeding widows have been designed and tested and the issues related to the reliability of PCB have been investigated.

Q.8.13
17:30
Authors : Michael Bernicke, Björn Eckhardt, Erik Ortel, Denis Bernsmeier, Roman Schmack and Ralph Kraehnert*
Affiliations : Technische Universität Berlin, Berlin, Germany

Resume : The synthesis of mesoporous NiO via stable NiCO3 intermediate is achieved by a soft templating approach utilizing PEO-PB-PEO triblock copolymers and evaporation induced self assembly. The well known excessive crystallization behaviour of NiO is avoided by the complexation of the nickel precursor Ni(NO3)2 with citric acid. Thermal properties of the polymer template, the nickel precursor complex and the stable NiCO3 intermediate are investigated by TGA. The prepared films on different substrates were investigated in terms of morphology, pore ordering, crystallinity, surface species and surface area by SEM, TEM, SAXS, SAED, XRD, XPS and Kr-physisorption. The electrocatalytic OER activity is examined in order to achieve insights into structure-activity relationships. Furthermore, we will show that a calcination temperature of 250 °C leads to an amorphous, stable NiCO3 intermediate. An increase of the calcination temperature results in mesoporous templated NiO with low crystallinity and high BET surface area as well as high OER activity. We will elucidate that the BET surface area is an important reaction parameter in order to obtain highly active OER catalysts.

Q.8.14
17:30
Authors : Jinhee Heo, Changman Kim, Jung Rae Kim
Affiliations : Korea Institute of Materials Science(KIMS), Advanced Characterization & Analysis Department, Changwon, Korea ; School of Chemical and Biomolecular Engineering, Pusan National University, Busan, Korea ; School of Chemical and Biomolecular Engineering, Pusan National University, Busan, Korea

Resume : Microbial fuel cell(MFC) systems use electrochemically active biofilm which can exchange electron discharged from internal metabolic pathway into electrically conductive electrode as terminal electron acceptor and/or donor. Conventionally MFC has been applied to produce renewable energy such as electricity and hydrogen from various biodegradable organic materials, and biosensor for organic contaminant monitoring. We investigated the effect of Ti nano-particle on the electron generating efficient of MFC by deposition of nano-particles on the carbon paper electrode. Since the generated voltage and current from MFC are depend on the amount of microbes which are attached on the anode, a surface area and bioaffinity of electrode materials are important factor. By monitoring the voltage of MFC which employing Ti-nano-particle, we evaluated and compared performance enhancement with a case of general carbon paper anode. Also, an influence of nano-particle size and gap of inter-particle variation were investigated. To understand a mechanism of electron transport from alive microbe to conductive electrode, we need to observe an individual electrochemically active bacterium such as Shewanella oneidensis MR-1 by using nano-probing technique. The electrical properties such like resistance and dielectric constant of microbes were analyzed by conductive-atomic force microscopy(C-AFM) with conductive cantilever tip and mini-structured MFC were employed for the in-situ characterization of internal reaction and property of MFC. To investigate an interaction between microbe and anode electrode with Ti nano-particle would be a clue for understanding of electron generation and transmission mechanism.

Q.8.15
17:30
Authors : Valeria Palomba, Mauro Prestipino, Antonio Galvagno
Affiliations : Valeria Palomba, CNR ITAE "N.Giordano", University of Messina-Department of Engineering; Mauro Prestipino, University of Messina-Department of Engineering; Antonio Galvagno, University of Messina-Department of Engineering

Resume : The aim of this study is to evaluate the feasibility of producing a combined heat and power system from woody biomass gasification unit coupled with a solid oxide fuel cell (SOFC). In particular, a downdraft air-gasification unit for syngas production and a tubular SOFC for heat and power production were considered. Both gasification and SOFC-CHP units were modeled via ASPEN plus in order to determine mass and heat balances and were validated with literature data. The SOFC electrical performances (polarization, power density and SOFC AC efficiency) were evaluated. The TRNSYS dynamic modelling features have been used to evaluate the most suitable technical solutions and to calculate all the energy streams and relevant parameters. Considering a compromise between feedstock consumption and capital costs, a 200 mA/cm2 current cell density was selected for the SOFC and the required syngas flow rate was calculated. Through the simulation model of the gasification unit, the amount of semi-dry (12% water content) woody biomass has been estimated to be about 413 kg/h for 635 kW of electricity produced by the SOFC. The gross AC efficiency of 40% was obtained. Based on simulations results, it was proved the theoretical possibility to obtain an added value from the energetic exploitation of woody biomass, through an integrated downdraft gasification unit and a 635 kW SOFC-CHP system. Through the employment of TRNSYS environment, a design model suitable for the technical, energetic and economic evaluation of the system has been developed, which represents a viable tool for detailed analysis on such systems.

Q.8.16
17:30
Authors : G Cespedes, M Asteazaran, A M Castro Luna
Affiliations : Centro de Investigación y Desarrollo en Ciencia y Tecnología de Materiales (CITEMA), Facultad Regional La Plata, UTN, La Plata, Argentina; Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, UNLP-CONICET, La Plata, Argentina

Resume : The heart of a fuel cell is the membrane-electrode assembly consisting of two porous electrodes (where the electrochemical reactions take place), and the ionomer conductive membrane (that allows the proton exchange from the anode to the cathode). The porosity of the electrodes plays an important role in the fuel cell performance. One of the drawbacks presented by the porous electrodes is the accumulation of water in their structure, which implies a hindrance for the reactive gas transport to reach the electrode active sites. Of the many parameters that play a part in improving the fuel cell behavior, the water content in the gas that fed the cathode is systematically studied in reference to fuel cell performance. In this work, a mathematical model is presented and discussed in which fuel cell operating under steady state and isothermal conditions together with a simple and uniform porous electrode structure is assumed. It is demonstrated that at low current densities, water accumulation has no effect in the fuel cell behavior, whereas at high current densities the cell performance is severely affected.

Q.8.17
17:30
Authors : C. Alegre, E. Modica, A.S. Aricò, V. Baglio
Affiliations : Istituto di Tecnologie Avanzate per l'Energia "Nicola Giordano" CNR-ITAE Salita Santa Lucia sopra Contesse, 5 98126 Messina (Italy)

Resume : The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are very important processes in different energy conversion devices such as electrolysers, unitized reversible fuel cells and metal-air batteries. Both reactions occur on the same electrode during the charge and discharge processes, what requires a “bi-functional” material able to carry out both reactions. Recently, perovskites have shown outstanding activities as bifunctional catalysts for both the ORR and the OER in alkaline medium. In the present work, a perovskite with formula La0.6Sr0.4Fe0.8Co0.2O3 (LSFCO) was mixed with a carbon material and investigated for operation as both oxygen reduction (ORR) and oxygen evolution (OER) catalyst. The catalyst was investigated in half-cell by using a three-electrode configuration, in alkaline solution at ambient temperature, and compared to a noble metal catalyst, Pd/C. LSFCO was less active for the ORR, while the performance for the OER was significantly higher compared to Pd. Several accelerated stress tests were carried out in order to investigate the stability of the catalyst. The LSFCO-based catalyst showed a very stable behavior compared to the noble metal catalyst.

Q.8.18
17:30
Authors : A. Stassi1, O. Barbera1, G. Giacoppo1, D. Sebastian1, C. D’Urso1, M. Schuster2, B. Bauer2, V. Baglio1, A.S. Aricò1
Affiliations : 1CNR-ITAE Institute for Advanced Energy Technologies "N. Giordano", Via Salita S. Lucia sopra Contesse 5, Messina 98126, Italy 2FUMATECH BWT GmbH, Carl-Benz-Strasse 4, Bietigheim-Bissingen D-74321, Germany

Resume : In the last few decades, direct methanol fuel cells (DMFCs) have been actively investigated from both fundamental and applied points of view. Recent results have shown interesting perspectives for the application in the fields of auxiliary power supply and portable power sources. Hundred-watt-class DMFC systems designed to supply power for medium-size electrical applications, such as small vehicles and emergency auxiliary power sources, have been investigated. The design and operation of these systems require the selection of proper components, stack design and experimental conditions. In this work, a new design of bipolar plates was developed for a 10-cell DMFC stack, with 100 cm2 cell area, for auxiliary power units (APUs) applications. The membrane-electrode assemblies (MEA) were manufactured by using a fumapem® F-1850 perfluorosulfonic acid membrane (from FUMATECH); whereas, nanosized carbon supported PtRu and Pt were used as anode and cathode electrocatalysts, respectively. To study the scalability of the DMFC stack and related components, a 5 cm2 single cell was used for the preliminary studies adopting the same MEA configuration of the 100 cm2 stacked cells. Different methanol feed concentrations were investigated both in single cell and stack configuration. The results obtained with the stack showed a good matching with the performance recorded with the small single cell, confirming the scalability of the DMFC device.

Q.8.19
17:30
Authors : Sung Mook Choi
Affiliations : Korea Institute of Material Science (KIMS)

Resume : Hydrogen (H2) has been recognized as a high energy density, efficient, and environmentally clean in a variety of renewable energy sources. However, production, storage, and transportation of H2 it involves some problems with regard to cost, safety, low hydrogen gravimetric density, and difficulty in hydrogen extraction. The H2 produced by water electrolysis in the on-site place can be an alternative compared to other way to solve these problems. In the water electrolysis area, the numerous researchers have been focused on the oxygen evolution reaction (OER) because the OER is a key anodic process (slow kinetics) compared with another process as hydrogen evolution reaction (HER) to produce H2. On a point of view of a catalyst, slow kinetics in OER and the use of precious metal (platinum group metal) for high performance should be solved to popularize water electrolysis. The target of this study is the development of non-precious catalysts with high activity via simple and efficient synthesis method that is a wet-chemical based method. The 0 dimensional transition metal oxide catalysts were synthesized through the co-precipitation. The electrocatalysts were characterized by various physicochemical analyses such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). To investigate electrocatalytic properties of prepared catalysts, we carried out electrooxidation activity measurements such as cyclic voltammetry (CV), linear sweep voltammetry (LSV), long-term stability test, and electrochemical impedance spectroscopy (EIS). The relationship between their physicochemical properties and electrocatalytic activities will be explored and discussed with respect to variation of dimension.

Q.8.20
17:30
Authors : F. Alcaide*, G. Álvarez, R. V. Genova-Koleva, H.-J. Grande, O. Miguel, A. Querejeta
Affiliations : IK4-CIDETEC, Paseo Miramón, 196, 08028 San Sebastián, Spain

Resume : Environmental concerns due to the increasing use of energy power sources based on fossil fuels have driven the development of fuel cell technologies. Polymer electrolyte membrane fuel cells (PEMFCs) are one of the most promising because their high performance and wide range of applications. To accelerate the inherent electrochemical reactions taking place inside the PEMFC: the anodic hydrogen oxidation and the cathodic oxygen reduction, the use of catalysts is required. Nowadays, platinum is still the catalyst of choice for both processes. However, its scarcity, high cost and some geopolitical issues could limit its availability and use in the future, preventing the large-scale commercialization of PEMFC systems. To overcome these potential difficulties and ultimately replace Pt in PEMFCs, R&D activities in non-platinum catalysts are carrying out. Particular attention is receiving those materials that contain Co and Fe transition metals, like chalcogenides, inorganic/nanocarbon hybrid materials, and metal/N/C catalysts, among others. Regarding transition metal chalcogenides, cobalt sulphides are one of the most active electrocatalysts towards the ORR in acidic media. In this investigation, we synthesized practical catalysts of composition MxS2/C, MxM’1-xS2/C (M = Co; M’ = Ni, Fe; C = MWCNTs), by one-pot synthesis hydrothermal method. Then, we studied their electrochemical behaviour towards the ORR in H2SO4 and H3PO4 aqueous solutions, to mimic the fuel cell environment found in low and high temperature PEMFC, respectively. The results showed an improved electrocatalytic activity using CoS2-based catalysts. Furthermore, effects of catalyst composition and stability issues were also discussed. Acknowledgement: The research leading to these results has received funding from the European Community’s Seventh Framework Programme (FP7/2012-2015) for the Fuel Cells and Hydrogen Joint Undertaking under grant agreement ARTEMIS no. 303482.

Q.8.21
17:30
Authors : F. Alcaide1*, G. Álvarez1, M.K. Daletou2, N. Gourdoupi3, O. Miguel1, S.G. Neophytides2, A. Querejeta1
Affiliations : 1IK4-CIDETEC, Paseo Miramón, 196, 08028 San Sebastián, Spain 2FORTH/ICEHT, Stadiou Str., Platani Achaias, 26504, Patras, Greece 3Advent Technologies SA, Stadiou Str. Platani Achaias, 26504, Patras, Greece

Resume : High temperature polymer electrolyte membrane fuel cells (HT-PEMFC) can operate at temperatures up to 220 °C, resulting in an increase of the overall system volume power density and efficiency, which makes HT-PEMFC very attractive for different applications. However, there are some critical challenges related to the long-term operation of these fuel cells, which need to be addressed. In particular, degradation observed in the cathode catalyst layer results in a loss of performance yielded by the fuel cell. To overcome this issue, a new approach based on the use of modified carbonaceous support for Pt nanoparticles dispersion has been followed in this investigation. Pt/MOx(CNT) electrocatalysts were synthesized from commercial multiwalled carbon nanotubes, modified by chemical oxidative treatment, and then coated with different metal oxides, MOx (M= Ce, Co, and Ti). Electrochemical characterization in three-electrode cell with H3PO4 shown enhanced electrochemically active surface areas compared to Pt/CNT reference catalysts, denoting decreased phosphoric acid poisoning. Furthermore, their in-situ performance (V-j curves) in H2|air single cell at 140, 160 and 180 °C, gave promising results, which was attributed to the modified cathode catalyst support. Acknowledgement: The research leading to these results has received funding from the European Community’s Seventh Framework Programme (FP7/2013-2016) for the Fuel Cells and Hydrogen Joint Undertaking under grant agreement DeMStack no. 325368.

Q.8.22
17:30
Authors : Navarra Maria Assunta1, Siracusano Stefania2, Baglio Vincenzo2, Nicotera Isabella3, Aricò Antonino Salvatore2
Affiliations : 1: Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy; 2: CNR-Institute of Advanced Energy Technologies (ITAE) - Via Salita Santa Lucia sopra Contesse, 5 - 98126 Messina, Italy; 3: Department of Chemistry and Chemical Technologies, University of Calabria, via P. Bucci, 87036 Rende (CS), Italy

Resume : Polymer electrolyte membranes (PEMs) have found useful applications in many energy-related fields, including hydrogen production by water electrolysis (WE) devices [1]. Electrolysis of water using a PEM, serving as both proton conductor and separator of gases, is considered an appealing alternative to more conventional alkaline water splitting technologies. State-of-the-art PEMs are perfluorinated systems, such as Nafion. These materials offer most of the needed properties for efficient PEM WE, i.e., high proton conductivity, good mechanical and electrochemical stability. However, they suffer from several drawbacks, mainly (i) cross-permeation phenomena, especially at high pressure, leading to contamination of oxygen by hydrogen and potentially to high risk levels and (ii) operating temperatures limited to 80 °C due to mechanical strength and proton conductivity losses. Goal of the present work is to develop new, more resistant PEMs exhibiting reduced gas permeation and operating in a wider temperature range, e.g., up to 100 – 120 °C. Indeed, extension of working temperatures may result in a better water and thermal management as well as in enhanced kinetics of the oxygen evolution reaction, which is the rate determining step of the whole process. To reach this goal, the modification of Nafion membranes by the incorporation of solid inorganic acid nano-particles has been considered [2]. As original contribution to the research on PEMs for water electrolysis, we here report on the use of sulfated titanium oxide, S-TiO2, having super-acidity properties and tunable morphologies, as membrane additives. The influence of the inorganic filler on the properties of composite Nafion membranes is investigated. Temperature-dependent electrochemical performances of SPE electrolyzers adopting bare or composite polymer electrolyte are here discussed in terms of polarization curves, cross-over currents and impedance response of the cells. [1] M. Carmo, D.L. Fritz, J. Mergel, D. Stolten Int. J. Hydrogen Energy, 2013, 38, 4901. [2] S. Siracusano, V. Baglio, M.A. Navarra, S. Panero, V. Antonucci, A.S. Aricò Int. J. Electrochem. Sci., 2012, 7, 1532.

Q.8.23
17:30
Authors : A.Di Blasi, G. Brunaccini, G. Dispenza, F. Sergi, L. Andaloro, N. Randazzo, V. Antonucci
Affiliations : CNR-ITAE

Resume : Electrochemical investigations on 1-2 kW experimental short stacks, consisting of different modified electrode configurations, were carried out under enriched-air conditions (> 23.5 % Oxygen) by using the current design stack technology. The aim was the electrochemical performance evaluation as a function of the oxygen compatibility in order to guarantee high standard levels in terms of safety, durability and feasibility. The interest was focused towards the performance evaluation under a 30% in oxygen for naval applications. This value was selected thanks to a preliminary investigation activity based on a risk analysis carried out at different oxygen percentages, by using materials and components data, consisting in the present stack technology in terms of hardware and software. Electrochemical characterizations performed on the experimental stacks assembled with different Pt loading under enriched-air condition (30% oxygen) showed an electrical efficiency enhancement of about 2% with respect to a commercial stack operating under standard condition (21% oxygen). In the perspective of overcoming the technology safety limit due to the current stack hardware and software components, the obtained result can offer large margin of improvement for operating conditions under more high oxygen percentage (> 30%).

Q.8.24
17:30
Authors : Maria Assunta Navarra A, Stefania Panero A, Gino Mariotto A, Sergio Brutti C
Affiliations : A Dipartimento di Chimica, Sapienza Università di Roma, P.le Aldo Moro 5, I-00185, Roma, Italy; B Dipartimento di Informatica – Università di Verona, Strada le Grazie 15, I-37134, Verona, Italy; C Dipartimento di Scienze, Università degli Studi della Basilicata, Via dell’Ateneo Lucano 10, I-85100, Potenza, Italy

Resume : Polymer electrolyte fuel cells based on Nafion membranes are able to work in a relatively low temperature range (70–100 °C) but require operating relative humidity (RH) close to 100% in order to allow effective proton conduction. In order to develop proton-exchange membranes with adequate performances at low RH an attractive strategy consists of the incorporation of inorganic acidic materials into the host Nafion polymer. Sulfated metal oxides are actually attracting much interest as fuel cell membrane additives [1]. This communication reviews our recent results concerning the characterization of nanosized TiO2 and SnO2 powders with high acidic properties to be adopted as fillers in Nafion-based polymer electrolytes. Taylor-made synthetic procedures have been assessed in order to obtain nanosized oxide materials with controlled morphologies and phase purity. Moreover surface treatments to bond sulphate groups on the oxide surfaces have been optimized. The obtained fillers have been characterized by thermal analysis (TGA), X-ray diffraction, N2-absorption, transmission electron microscopy and vibrational spectroscopies (Raman and FT-IR). The sulphated oxide nanoparticles have been incorporated in Nafion polymer membranes by a solvent-casting procedure. Structural, morphological and vibrational properties of the sulphated composite membranes have been investigated by advanced techniques including TGA, atomic force microscopy, Raman and IR spectroscopies. Functionality of the proposed membranes has been demonstrated by electrochemical in-situ (as electrolytes in a fuel cell device) and ex-situ (for proton conductivity tests) characterizations. [1] A. D'Epifanio, M.A. Navarra, F. Weise, B. Mecheri, J. Farrington, S. Licoccia, S. Greenbaum, Chem. of Materials, 22 (2010) 813

Q.8.25
17:30
Authors : K. Ćwiekaa, T. Wejrzanowskia, J. Milewskib, K. J. Kurzydłowskia
Affiliations : aFaculty of Material Science and Engineering, Warsaw University of Technology, 141 Woloska Street, 02-507 Warsaw bInstitute of Heat Engineering, Warsaw University of Technology, 21/25 Nowowiejska Street, 00-665 Warsaw

Resume : Efficiency of Molten Carbonate Fuel Cells (MCFC) is strongly associated with the microstructural characteristics of their components. Design of MCFC materials demands determination of quantitative relationships between the structure and operational efficiency of the cell. All the elements including cathode, anode and matrix are highly porous in order to facilitate catalytic and transport phenomena. Required porosity level is strictly determined by kinetics of chemical reactions in case of the electrodes. Porosity, as a crucial feature for each of main MCFC components, can be obtained by tape casting of metallic powder suspended in the polymer based slurry and further firing. The present paper presents the results of the optimization of manufacturing parameters and characterization of the anode materials obtained herewith using tape casting technique. In this method green tapes are formed from a slurry with strictly defined composition and properties. Subsequent stages of the manufacturing process, including: slurry composition optimization, tape casting set-up and heat treatment parameters, were carried out. Proper combination of slurry ingredients allows to achieve optimal structural characteristics of final products. The influence of the slurry composition and heat treatment conditions are correlated with structural parameters such as porosity of final products. In order to establish structure-property relationships the materials fabricated here were tested in MCFC assembly with respect to their efficiency. Anodes of various porosity and thickness were tested. Performance tests demonstrated that an adequate architecture of the anode allow to generate the power in the unit cell from 3.7 mW/cm2 to 4.9 mW/cm2 at 650 °C in humidified hydrogen.

Q.8.26
Start atSubject View AllNum.Add
12:30 Lunch Break    
 
SESSION IX : Stefania Specchia
14:00
Authors : Eliana Quartarone
Affiliations : Dept. of Chemistry, Division of Physical Chemistry University of Pavia

Resume : Proton exchange membranes (PEMs) are ionically conductive polymers, typically employed in a wide range of applications, as for instance fuel cells. In this kind of technology, the membrane acts as a separator through which protons migrate with different mechanisms, typically vehicle- or Grotthus ones, depending on both the chemistry and physics of the starting polymer. Generally, NafionTM is the most investigated membrane electrolyte for fuel cells and still represents a benchmark to consider when a new system is proposed as alternative PEM. The state-of-the-art of Nafion as part of a fuel cell is impressively wide. It was extensively employed either in chemical fuel cell or microbial ones. The reason lies in a number of advantages offered by such polymer, such as the high proton conductivity, the low internal resistance and a good chemical stability. On the other hands, PEMs based on NafionTM are expensive; therefore they are not economically sustainable. In addition, they show a number of critical drawbacks, depending on the type of applications, as for instance: i) conductivity drops at temperature exceeding 100°C and humidification issues in case of chemical fuel cells; ii) chemical/biological fouling and high transfer ratio of substrate cations to protons in case of microbial fuels cells. In both the systems, these factors hinder the cathode electrochemical processes and drastically reduce the device functional performances. The current target on PEMFC R&D is the overcoming of such constraints. To this aim, the investigation of innovative and advanced materials could be a successful approach, either in the field of chemical fuel cells or MFC. Polybenzimidazole is the more attractive alternative to NafionTM. It is a cheap polymer, easy to synthetize and process, chemically stable and is a good proton conductor. In case of chemical PEMFCs, acid-doped Polybenzimidazoles are actually considered as promising electrolytes to replace Nafion in HT-PEMFCs. Nevertheless, some relevant questions are still open: under which operating conditions (chiefly temperature) are the acid-doped PBI systems a real alternative to Nafion? What is the real durability of the PBI cells/stacks? For what concerns the microbial PEMFCs, very isolated information is still available in literature about PBI membranes as potential separator for MFCs. Here I will report the state of the art and most recent developments of my group on polybenzimidazole systems in two cutting-edge technologies of green economy and bioenergy, namely high temperature (HT)-PEMFCs and Microbial Fuel Cells. Particular emphasis is given to some questions, which are still critical and open, as well as to the strategies adopted in my laboratory to properly address these issues.

Q.9.1
14:30
Authors : D. Herranz, R. Escudero-Cid, M. Montiel, E. Fatás, P. Ocón
Affiliations : Departamento de Química Física Aplicada, Universidad Autónoma de Madrid, C/ Francisco Tomás y Valiente 7, Madrid (España)

Resume : In recent years, polymer electrolyte membrane fuel cells (PEMFC) are attracting great interest due to the high power densities that are capable of reaching at relatively low temperatures. Hydrogen and methanol have been the most common fuels used in these devices but both have certain drawbacks1. Nowadays, one of the best alternatives to these fuels is the use of ethanol, easy to store and distribute, cheaper and less toxic than methanol. In addition, ethanol is considered a green chemical and it can be produced as a renewable biofuel from the fermentation of biomass in large quantities. However, direct ethanol fuel cells (DEFCs) have important drawbacks as the slow electrode kinetics or the high cost of electrocatalysts in acidic media2. The use of alkaline membranes could improve the reaction kinetics and facilitate the use of a range of non-precious metal catalysts both in the cathode and in the anode, reducing the dependence of platinum and so the cost of the catalysts, in addition to an important decrease of alcohol permeability3. These advantages are the main reason to change the common type of PEMFC devices to others with anion exchange membranes as electrolytes. However, the main issue of the improvement of the performance of these fuel cells was the limited development of the anion exchange polymeric membranes (AEMs). In the present research, we report a comparative study of new composite PVA/PBI membranes synthesized in different proportions (2:1, 4:1, 6:1 and 8:1) using the casting method and doped with KOH in order to study their suitability for fuel cell applications. These materials have been characterized by FT-IR/ATR and Raman spectroscopy. Thermal stability, water and KOH uptakes have also been determined. The ionic conductivity of the doped membranes is between 10 2 and 10 1 S·cm 1. These results are suitable to use these composite membranes in anion exchange membrane DEFCs. In fact, the highest power density value obtained in single cell measurements is 76 mW cm-2 for PVA/PBI 4:1, giving a power density 50% higher than the doped PBI in the same conditions. References: [1] Oliveira Neto A., Giz M.J., Perez, J. et al., Journal J. of the Electrochemical. SocietySoc., 149: A272-A279, 2002 [2] Geraldes A.N., Furtunato da Silva D., Martins da Silva J.C. et al., Journal of . Power Sources, 275: 189-199, 2015 [3] Varcoe J.R., Slade R.C.T., Yee E.L.H. et al., Journal J. of Power Sources.;, 173:194-9, 2007

Q.9.2
14:45
Authors : Vito Di Noto 1,2,*, K Vezzù 1, E. Negro 3,4, F. Bertasi 1, A. Bach Delpeuch 1, G. Nawn 1, Y. Bang 1, G. Paggot 1,4, C. Shun 1, G. Pace 2
Affiliations : 1 Department of Industrial Engineering, University of Padova, Via Marzolo 9, 35131 Padova, Italy 2 CNR-ICMATE, Via Marzolo 1, 35131 Padova, Italy 3 Department of Chemical Sciences, University of Padova, Via Marzolo 1, 35131 Padova, Italy 4 Centro Studi di economia e tecnica dell'energia “Giorgio Levi Cases”, Via Marzolo 9, 35131 Padova, Italy

Resume : Ionically conducting materials (ICM) are of great importance for the fabrication of portable batteries for electronic devices such as computers, tools, video and still cameras, and for the development of fuel cell and battery-powered electric vehicles, dye-sensitized solar cells, supercapacitors and sensors. It has been suggested that conductivity in ICMs occurs via a number of different processes. The predominant conductivity processes are attributed to: a) the charge migration of ions between coordination sites in the host materials; and b) the increase of conductivity due to relaxation phenomena involving the dynamics of the host materials. Ions “hopping” to new chemical environments can lead to successful charge migration only if ion-occupying domains relax via reorganizational processes, which generally are coupled with relaxation events associated with the host matrix. In the first part of this presentation will review the general phenomena and basic theory behind Broadband electric spectroscopy. Then an overviews of the application of BES in the study of the charge transfer mechanisms pristine and hybrid inorganic-organic proton-conducting and anion-conducting membranes for fuel cells, the models adopted for the interpretation of conductivity mechanisms are described and a unified conductivity mechanism is proposed. Acknowledgements The authors thank the Strategic Project “From materials for Membrane electrode Assemblies to electric Energy conversion and SToRAge devices” (MAESTRA) of the University of Padova for funding this activity.

Q.9.3
15:00
Authors : F. Lufrano1*, I. Nicotera2, C. Simeri2, P. Staiti1, A.S. Arico’1, V. Baglio1
Affiliations : 1* CNR-ITAE, Istituto di Tecnologie Avanzate per l’Energia “Nicola Giordano”, Via Salita S. Lucia sopra contesse n. 5, 98126 S. Lucia – Messina Italy. 2 Department of Chemistry, University of Calabria, 87036 Rende (CS), Italy.

Resume : Acidic polymer electrolytes based on perfluorosulfonic-acid membranes are extensively used as electrolytes (e.g. Nafion-type membranes) in many electrochemical power applications, but high cost, low operating temperature and high methanol crossover of Nafion membranes limit their wide applications [1,2]. These drawbacks are pressing scientists to develop new composite polymer electrolyte membranes (PEMs) based on sulfonated aromatic polymers as alternatives to Nafion for DMFC applications. This study reports on the synthesis and development of PEMs based on composite membrane of sulfonated polysulfone and modified silica materials for application in DMFC at different operating temperatures. The sulfonated polysulfone (SPSf) is easily synthesized by using trimethyl silyl chlorosulfonate as sulfonating agent in a homogeneous phase of chloroform [3] and, the functionalized silica was prepared by reacting silica with neat chlorosulfonic acid at room temperature[4]. The ion exchange capacities (1.2 -1.8 meq g-1) of sulfonated polymer samples were obtained changing the mole ratio between the sulfonating agent and monomer unit of polymer. The structural and physical chemical features of the composite membranes were assessed by scanning electron microscopy, infrared spectroscopy and NMR measurements. Besides, the transport properties of the water and methanol through the electrolyte membranes as a function of methanol concentration (e.g. 1M - 5M CH3OH) and temperatures from room temperature up to 80°C were obtained by NMR and methanol/water uptake methods. Instead, the electrochemical features of membranes in terms of proton conductivity and DMFC performance at various temperatures were evaluated by polarization and ac-impedance spectroscopy (EIS) measurements. The whole study involved (a) the choice of preparative conditions to optimize the synthesis and yield of produced sulfonated polysulfone polymer, (b) the modification of silica and the optimization of acidic silica content in the composite membrane, (c) the assessment of structural and water/methanol transport properties through the membranes by using pulsed-gradient spin-echo (PGSE) NMR diffusion method under variable temperature and d) DMFC single cell investigations at different methanol concentration (e.g. 1-5 M) and temperatures. The first important finding of the work was obtained by NMR measurements, which showed higher water diffusion than methanol diffusion in all the three investigated membranes (composites and bare SPSf) and for different methanol solution concentrations (1-5M) and temperatures (30-80°C). Moreover, the study showed that as the temperature increases, the difference in diffusion coefficient become larger for the composites, proving the beneficial methanol blocking effect of the silica nanoparticles dispersed in the polymer matrix. The lower diffusion coefficient of acidic silica composite membrane than other membranes was also confirmed by in-situ measurements such as linear sweep voltammetry, by the limiting crossover current, and EIS under potentiostatic mode at 0.3 V. Both techniques showed that the best DMFC performance of SPSf-SiO2Sulf membrane was due more to its low permeability than to the high proton conductivity. The comparison of polarization curves show clearly that the MeOH crossover is the controlling phenomena occurring in DMFC that maximize the electrochemical performance, at least in the experimental conditions of measurements. A power density of 30 mW cm-2 was recorded at 60°C feeding 5M methanol solution at the anode and dry air at the cathode, both at atmospheric pressure. These interesting electrochemical features are indicating good perspectives of these membranes in practical DMFC for auxiliary power unit applications. References [1] J. Martin, W. Qian, H. Wang, V. Neburchilov, J. Zhang, D. Wilkinson, Z. Chang, Journal of Power Sources, 164 (2007) 287-292. [2] C. Laberty-Robert, K. Valle, F. Pereira, C. Sanchez, Chemical Society Reviews, 40 (2011) 961-1005. 3. F. Lufrano, V. Baglio, P. Staiti, A. Stassi, A.S. Arico’, V. Antonucci, J. Power Sources 195 (2010) 7727-7733. 4. M.A. Zolfigol, Tetrahedron 57 (2001), 9509-9511.

Q.9.4
15:15
Authors : Giovanni Zafarana1*, Susanna Maisano1, Francesco Urbani1, Mauro Prestipino2 and Vitaliano Chiodo1
Affiliations : 1Institute CNR-ITAE, via Salita S. Lucia sopra Contesse 5, 98126 - Messina – Italy 2Department of Engineering, University of Messina, C. da Di Dio 98158, Messina – Italy

Resume : The exploitation of agro-industrial residues for syngas production through gasification process has attracted many interests in the sustainable energy for future developments in order to reduce the dependence from fossil fuels. Fruits processing industries generate important amount of residues, which must be managed properly by recycling, incineration or land filling. Particular attention has been recently addressed toward the use of residual biomass and wastes as sources for syngas production by thermo-chemical processes for heat and power production. In this context, thermo-gravimetric measurements of citrus residues (under nitrogen and steam atmosphere) allowed the selection of suitable gasification conditions (T≥720°C; S/B≥1.5 wt/wt). Therefore, steam gasification process of citrus waste was investigated from thermodynamic and experimental point of view. Experiments were carried out in a lab-scale reactor in presence of different catalytic materials (Ni/Al2O3, MgO and dolomite mineral). Results highlighted the effects of catalysts on outlet gas stream compositions mainly in terms of hydrogen content. In particular, gasification tests performed with dolomite get an H2 selectivity of about 84 vol%. Experimental results were also compared to thermodynamic data by process simulator software (Aspen Plus).

Q.9.5
15:30 Coffee Break    
 
SESSION X : Maria Assunta Navarra
16:00
Authors : Sergey Grigoriev1, Vladimir Fateev2, Vladimir Markelov2, Waldemar Mróz3, Bogusław Budner3
Affiliations : 1 National Research University "Moscow Power Engineering Institute", Krasnokazarmennaya str., 14, Moscow, 111250, Russia; 2 National Research Centre "Kurchatov Institute", Kurchatov sq., 1, Moscow, 123182, Russia; 3 Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego str., 00-908, Warsaw, Poland

Resume : The aim of this communication is to report on application of various plasma-assisted sputtering for the synthesis of electrocatalysts and electrocatalytic layers for proton-exchange membrane (PEM) electrochemical systems (fuel cells, water electrolysers, etc). Targets based on platinum metals have been sputtered over the surfaces of membrane, gas diffusion electrode (carbon cloth, carbon paper of porous titanium) or nano-dispersed catalysts carrier using several physical techniques such as ion-beam and pulsed laser deposition. Synthesized electrocatalytic materials have been studied by transmission and scanning electron microscopy, X-ray diffraction analysis, X-ray absorption spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis and cyclic voltammetry. They were also tested in PEM water electrolysis and fuel cells. Features of plasma-assisted catalysts deposition are discussed. Development of magnetron-ion sputtering technique was executed with financial support of the Russian Science Foundation (project No. 14-29-00111). Investigations of developed electrocatalytic materials have been financially supported by the Ministry of Education and Science of the Russian Federation within the framework of government task No. 2014/123 for performance of the government works in scientific activities.

Q.10.1
16:30
Authors : Vincenzo Baglio, Sabrina C. Zignani, David Sebastian, Ada Saccà, Irene Gatto, Antonino S. Aricò
Affiliations : CNR-ITAE, Salita S. Lucia sopra Contesse 5 – 98126 Messina, Italy

Resume : Large scale application of polymer electrolyte membrane (PEM) fuel cell system technology requires a reduction of its high cost as well as improvement of performance and stability. In particular, for engineering requirements, PEM fuel cells for automotive application need to operates under harsh condition such as high temperatures, i.e. 110 °C or above, and low relative humidification (R.H.) less than 50%. These extreme conditions require the development of catalysts with proper resilience to sintering and corrosion. In addition, to reduce the total cost it is necessary to minimize the platinum content in the membrane electrode assembly (MEA) maintaining at the same time good performance. With these aims, in the last years at the CNR-ITAE Institute the research activities were focused mainly on the development of various platinum-based eletrocatalysts characterized by a good performance and proper resistance to sintering and corrosion [1-3]. In the present work, carbon supported Pt-Ni (differently alloyed) catalysts have been prepared by using the formic acid reduction method and characterized in terms of bulk and surface composition, structure and morphology. They have been investigated in PEFCs under automotive conditions (high temperature and low R.H.) and compared to a benchmark Pt/C catalyst. Accelerated degradation tests were also carried out to evaluate electrocatalysts stability. Acknowledgements The research leading to these results has received funding from the European Union’s Seventh Framework Programme (FP7/2007-2013) for Fuel Cell and Hydrogen Joint Technology Initiative under Grant no 303452 (IMPACT). References 1. A. Stassi, I. Gatto, G. Monforte, V. Baglio, E. Passalacqua, V. Antonucci, A.S. Aricò, J. Power Sources 208 (2012) 35. 2. A. Stassi, I. Gatto, V. Baglio, E. Passalacqua, A.S. Aricò, J. Power Sources 222 (2013) 390. 3. A. Stassi, I. Gatto, V. Baglio, A.S. Aricò, Int. J. Hydrogen Energy 39 (2014) 21581.

Q.10.2
17:00
Authors : Yan Busby 1, Mathieu Da Silva 1, Vaios Stergiopoulos 2, Nathalie Job 2, Laurent Houssiau 1, Jean-Jacques Pireaux 1
Affiliations : 1 University of Namur, Research Center in Physics of Matter and Radiation (PMR - LISE), 61, rue de Bruxelles, 5000 - Namur (Belgium) 2 University of Liège, Chemical Engineering, Nanomaterials - Catalysis & Electrochemistry, Sart-Tilman, 4000 - Liège (Belgium)

Resume : Large scale production of proton-exchange membrane fuel cells (PEMFCs) is mainly limited by the high cost and the high environmental impact of platinum-based catalysts. A higher control on Pt nanoparticles (NPs) density and morphology are mandatory while preserving an easy, scalable and environmental friendly deposition method. The synthesis of Pt/C catalysts by (wet) chemical routes are difficult to upscale and frequently require the use of organic solvents and surfactants which can lead to device failure due to the poisoning of Pt NPs. In this work, catalysts for PEMFCs applications are synthetized by using low-pressure RF plasma treatments [1], ensuring a fast and easy synthesis not requiring any use of solvents. The plasma discharge is applied to generate structural and chemically active defects at the surface of different nanostructured carbon supports where the simultaneous nucleation of metal nanoparticles occurs from the degradation of an organometallic powder precursor (platinum acetylacetonate). Furthermore, gram quantities are achievable in a laboratory-scale reactor. The organometallic precursor and the carbon solid powders are mixed and then continuously stirred during the plasma treatment; this ensures a homogenous decoration of the high-surface-area carbon nanomaterial (graphene nanoplatelets, carbon nanotubes and xerogels) by metal NPs. The treatment conditions such as the plasma discharge power, treatment time and chemical environment have been optimized to end up with a uniform and dense distribution of metal NPs with a controlled size (around 5 nm) and low particle aggregation. The catalysts have been systematically characterized by electron microscopy (SEM, TEM and analytical STEM-EDX), X-Ray diffraction, and High Resolution X-Ray photoelectron spectroscopy (XPS). Measurements of the electrochemical activity versus the oxygen reduction reaction show equal or superior performances of plasma catalysts with respect to commercial Pt/C catalysts. An advantage of plasma synthesis is that nitrogen functionalization of the carbon material can be simultaneously performed by applying N2 plasma treatments: N loadings up to 5 at% (as measured by XPS) were achieved. Finally, Pt-Ni bimetallic catalysts have been realized by mixing the respective organometallic precursors. Interestingly, for a bimetallic Pt-Ni/C catalyst, a catalytic activity comparable to that of Pt/C catalysts with a higher Pt content has been obtained. [1] M. Laurent-Brocq, N. Job, D. Eskenazi, J.-J. Pireaux, Applied Catalysis B: Environmental, 147, (2014) 453-463

Q.10.3
17:15
Authors : Sang-Il Choi
Affiliations : Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, Daegu 702-701, Korea

Resume : Hydrogen evolution reaction (HER) consumes massive electrical energy in an alkaline electrolyte system during water and chlor-alkali electrolysis. Therefore, development of an active Pt-based electrocatalyst is remained as the great challenge to overcome the sluggish kinetics of alkaline HER. Recently, several reports demonstrated a promising strategy for enhancing the alkaline HER kinetics by depositing Ni(OH)2 clusters on the surface of a Pt catalyst. In this bimodal surface, the edges of oxophilic Ni(OH)2 catalyze the dissociation of water and the formation of hydrogen intermediates, while the nearby Pt surface converts the hydrogen intermediate to H2 gas. In this presentation, we have developed effective electrocatalysts based on Pt-Ni octahedra, where Ni(OH)2 was naturally formed on their surfaces during a synthesis. The as-obtained Pt-Ni octahedra show greatly enhanced HER activity in an alkaline solution compared to that of a commercial Pt/C catalyst.

Q.10.4
Start atSubject View AllNum.Add
 
SESSION XI : Sergey Grigoriev
09:00
Authors : Luigi Osmieri1,2, Alessandro H.A. Monteverde Videla1, Ricardo Escudero Cid2, Pilar Ocon2, Stefania Specchia1
Affiliations : 1 Politecnico di Torino, Dept. of Applied Science and Technology, Torino, Italy 2 Universidad Autónoma de Madrid, Department of Applied Chemistry Physics, Madrid, Spain

Resume : Direct alcohol fuel cells (DAFC) are attractive power generator systems for stationary and portable applications. The major drawbacks of DAFC technology stand with the sluggish anode/cathode reactions and the crossover of unreacted alcohol permeating through the membrane and reaching the cathode side, decreasing the entire fuel cell performance. The use of methanol-tolerant non-noble metal (NNM) catalysts based on transition metals (Fe, Co) and N-doped carbon is a costly and advantageous solution. NNM catalysts are less active than PGM ones, but they do not suffer from CO or methanolic species poisoning. In this work, Iron phthalocyanine (FePc) was used as Fe/N/C source and templated with an ordered mesoporous silica (SBA-15), followed by heat treatment and leaching of silica with hydrofluoric acid (sacrificial method) [1]. The catalyst was fully characterized and tested in an RDE configuration. Then, MEAs containing the Fe-N-C were prepared with Nafion® and PBI membranes and tested in single cell DMFC/DEFC under different alcohol concentrations and temperatures. A commercial Pt-Ru black was used at the anode side. The experiments were performed using 3 bar-g back pressure in the cathode compartment. The optimal operating condition was found to be 1 M (methanol) and 2 M (ethanol) at 90 °C, reaching 19.6 mW cm–2 for DMFC and 74.7 mW cm–2 for DEFC, respectively. Potentially, DEFC has larger activity performance than DMFC, using the same catalyst, suggesting system optimization progress to achieve activity increasing. At similar operating conditions, Pt-based cathodes are dramatically affected by permeated alcohol, by reducing their activity. [1] AHA Monteverde Videla, L Osmieri, M Armandi, S Specchia, Electrochim Acta 177, 2015, 43.

Q.11.1
09:30
Authors : Jesús Adrián Díaz-Real, José Ángel Huerta-Rosaldo, Luis Gerardo Arriaga-Hurtado
Affiliations : Centro de Investigación y Desarrollo Tecnológico en Electroquímica S.C.

Resume : A Ni/TiO2 electrocatalyst was synthesized and evaluated for its application in methanol oxidation in alkaline media. In brief, TiO2 nanotubes (TiO2-NT) were synthesized by electrochemical anodization from Ti foil which were used as substrate to later be deposited with Ni nanoparticles by cyclic voltammetry. An experimental factorial design was carried out to know the influence of potential range, scan rate and cycle number for Ni electrodeposition in the response for MeOH oxidation. Further on, the impact of nanotube length and the pre-treatment in acid media for the same reaction was assessed. For optimized conditions, scanning electron microscopy (SEM) and XRD revealed the presence of spherical Ni particles of an average value of 200 nm over the surface of the NT. Potential range was the most critical value in the study, while the number of cycles and scan rate exhibited to be in a competition where at higher scan rate the yield in methanol electrooxidation was increased. The NT length showed an important role in the maximum peak current demonstrating that longer geometries in the substrate enhance the reaction yield. Such behavior suggests that the NT are available and exposed to the electrolyte and organic molecule. These observations lead to the optimized combination of parameters for both electrocatalyst and support in the methanol oxidation.

Q.11.2
09:45
Authors : Jessica Thery, Erwan Coz, Vincent Faucheux, David Alincant, Philippe Capron
Affiliations : CEA/LITEN/DTNM/SENCI/LMSE

Resume : Depending from the energy density of the fuel, micro fuel cells could present an interesting alternative to batteries for powering of nomad devices. Various designs were proposed, all underlining the sensitivity of the breathing fuel cells performances to the environment. The water management in these breathing fuel cells is indeed even more pronounced since the cathode is in ambiant conditions. We developed a planar fuel cell array based on a printed circuit board as collectors, with integrated interconnection elements to be compatible with the voltages requirements of conventional electronic devices. The present design behave differently from the classical stack architectures since the interconnection elements are in the plane of the array. The obtained 6g fuel cell is able to deliver 5W in stable condition, at a yield of 48%. Neutron imaging studies have been performed at various yields during short term and long term operation. Nucleation mechanisms have been found hugely affected by the interconnection and packaging elements as well as natural convection. Understanding the nucleation mechanisms led also to the development of water management solutions for improved degradation rate, which is one of the limitation of fuel cells based on Printed Circuit Board designs. With this design, promising durability results have been obtained. We will discuss the correlation between water patterns and electrochemical performances. Degradation mechanisms during short term and long term operation will also be presented.

Q.11.3
10:00
Authors : I. Velázquez-Hernández,1 L. Álvarez-Contreras,2 M. Guerra-Balcázar,3 J. Ledesma-García,3 L.G. Arriaga1, M. Oropeza-Guzmán,1 N. Arjona 1*
Affiliations : 1Centro de Investigación y Desarrollo Tecnológico en Electroquímica S.C., Unidad Tijuana, Tijuana, B.C. C.P. 22444, México 2Centro de Investigación en Materiales Avanzados S.C., Complejo Industrial Chihuahua, Chihuahua, Chi. C.P. 31109, México. 3Facultad de Ingeniería, División de Investigación y Posgrado, Universidad Autónoma de Querétaro, Querétaro, Qro. C.P. 76010, México.

Resume : In this work, Pd nanoparticles as well as PdFe, PdAu and PdPt nanocatalysts were synthesized via a green reduction method using 2-hydroxy ethylammonium formate ionic liquids as an “all-in-one” reaction medium. Crystallite and nanoparticle sizes were in well concordance finding values of 10.1, 10, 11.8 and 7.9 nanometers for Pd, PdFe, PdAu and PdPt, respectively. For PdAu, it was observed the presence of planes related to palladium and gold indicating that, some proportion of the catalyst is only physically mixed. Moreover, the XRD of PdFe revealed that this material was mainly composed of Pd-Fe2O3. The electrocatalytic activity for the ethanol oxidation reaction was carried out as function of concentration and working temperature. AuPd/C showed the most negative oxidation potential and a current density almost two-fold higher than Pd/C, and similar than that obtained for PdFe/C. Furthermore, PdPt/C showed a lower poisoning effect than the other catalysts, this behavior was studied by Surface-Enhanced Raman Spectroscopy (SERS).

Q.11.4
10:15
Authors : Nicolò S. Vasile, Alessandro H.A. Monteverde Videla, Stefania Specchia
Affiliations : Politecnico di Torino, Dept. of Applied Science and Technology, Torino, Italy

Resume : The use of liquid fuels can be an attractive solution for supplying energy in portable devices. Direct Methanol Fuel Cell (DMFC) offers high theoretical power density. One way to control reactants distribution and the fluid dynamic regime is the use of different types of flow field (FF), both at anode and cathode. FF allows both supplying fuels and controling the diffusion of reactants for the electrochemical reaction, and removing products. Fluid flow in the FF can greatly affect the performance and life span of DMFC. In this study, the influence of three conventional and a modified FF designs on the performance of a DMFC was analyzed using a 3D multi-physics, multi-phase, multi-component and non iso-thermal model. The model includes Stokes-Brinckman, Darcy-Law, Maxwell-Stefan, Flory-Huggins and non-linear Butler-Volmer/Tafel equations for simulating the performance of a DMFC single cell, and to perform the electrochemical, fluid-dynamics and thermal phenomena. The model uses Comsol® Multiphysics v4.4 platform. All experiments for the model validation were carried out using a small-scale laboratory single cell DMFC with external areas of 5 and 25 cm2, for 3 different commercial flow field pattern: serpentine, convective and labyrinth. Experiments were performed by varying temperature and backpressure, using Nafion membrane, a commercial catalyst at the anode and a non-noble metal catalyst at the cathode.

Q.11.5
10:30 Coffe Break    
 
SESSION XII : Enrico Traversa
11:00
Authors : Emiliana Fabbri
Affiliations : Electrochemistry Laboratory, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland

Resume : In recent years, electricity-driven hydrogen production by electrochemical splitting of water has received particular attention because of its potential applicability in decentralized energy storage concepts.1,2 Most of the efforts have been focused on the electrochemical reaction occurring at the anode side, the oxygen evolution reaction (OER), since it is source of large overpotentials. Advances in computational studies and in in situ characterizations can now offer novel insights into the OER mechanism, revealing new perspective in the search for advanced materials. In this study, we couple a cutting-edge synthesis method to produce highly active OER nano-catalysts with advanced, time resolved X-ray absorption spectroscopy measurements able to capture snapshots of the catalyst electronic and local structure during operando conditions. The use of nano-catalysts not only allows achieving outstanding performance, but also reveals electronic and structural changes at the catalysts surface (given the high surface to bulk ratio of nanoparticles) never observed before. At present most of the fundamental studies on OER catalysts have been conducted using bulk techniques and materials with low surface area, which is a questionable approach considering that the OER is a near-surface reaction. In here we show that substantial and mostly irreversible chemical and structural changes take place on the catalyst surface at potentials where the OER occurs, opening new views on the OER mechanism. 1. Fabbri E, Habereder A, Waltar K, Kotz R, Schmidt TJ., Catal Sci Technol 2014, 4: 3800-3821. 2. Fabbri E, Nachtegaal M, Cheng X, Schmidt TJ, Advanced Energy Materials 2015, 5(17) 1402033

Q.12.1
11:30
Authors : Kapil Sood, Suddhasatwa Basu
Affiliations : Department of Chemical Engineering, Indian Institute of Technology, Delhi-110016, India.

Resume : As the world population is increasing continuously, the energy demand is becoming a major challenge for the world’s energy sector. At present, energy supply mainly depends on fossil fuels which are directly related to environmental pollution. Moreover, the nuclear disaster in Fukushima, Japan in 2011 has diverted world’s attention to alternative fuel resources. Under this situation, substitutes for conventional fuel sources are in major trust areas in current research and technology. One of the alternatives to fossil fuels is solid oxide fuel cells (SOFCs). SOFCs have attracted wide attention due to its high efficiency, fuel flexibility and minimum carbon emission. SOFCs are the class of fuel cells that are mainly based on solid oxide electrolyte. The most extensive electrolyte used for SOFC is YSZ, although high operating temperature nearly 800C is required to achieve sufficient oxide-ion conductivity. High operating temperature of these cells lead to many problems related with material stability and compatibility with other components of SOFCs and also thermal degradation of the electrolyte itself. Therefore, now considerable attention is given in developing solid electrolytes which can operate at intermediate temperature range (600-800C). Na-doped SrSiO3 has been investigated for its use as solid electrolyte. Sr1-xNaxSiO3- (x=0.0, 0.10, 0.20, 0.30 and 0.40) have been synthesized by simple solid state reaction method. The X-ray diffraction study indicated the formation of monoclinic phase. Raman analysis is performed to support the XRD results. AC impedance spectroscopy is used to study the conductivity of the system. Sr0.6Na0.4SiO3- showed highest conductivity of 22.8 mS/cm at 800 C in air. The SEM analysis indicated that secondary phase is co-formed, which is segregated along the grain-boundary regions. DSC analysis further supported the formation of amorphous phase.

Q.12.2
12:00
Authors : Yevgeniy (E.N.) Naumovich 1, Aleksey Yaremchenko 2, Javier Macías 2, Jorge Frade 2
Affiliations : 1-Institute of Power Engineering, Thermal Processes Department Augustówka 36, 02-981 Warsaw, Poland; 2-CICECO – Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro, Portugal;

Resume : Donor-doped strontium titanates demonstrate remarkable structural stability against redox cycling and are considered as promising components for SOFC anodes targeted for sulfur-contaminated and partially-reformed fuels. One important issue in the development of SrTiO3-based anode materials relates to the mechanism of adoption of excessive oxygen, which has do be introduced in perovskite lattice to compensate donor dopant. In the present work, we consider the formation of various types of defects in Sr(Ti,Ta)O3 solid solutions, including point defects as well as continuous cases: defect associations and intergrowth of strontium tantalate layer. The Monte-Carlo simulation and static lattice energy minimization techniques were used to find an optimal configuration of the lattice for solid solutions with Ta content up to 35 at.%. The perovskite lattice with embedded Sr2Ta2O7-like layers was found to be most stable, whilst the formation of the oxygen interstitials is rather improbable, neither in the form of 1D nor as 2D continuous defects. Charge compensation through the generation of cation vacancies demonstrated an intermediate thermodynamic stability. The results of atomistic simulations are discussed in combination with the experimental results on structural, electrical and redox properties of Sr(Ti,Ta)O3 solid solutions. Support from Polish Ministry of Science and Higher Education (stat. grant no. CPC/4/STAT/2016) is gratefully acknowledged.

Q.12.3
12:15
Authors : Ziya Çağrı Torunoğlu, Doğancan Sarı, Y. Eren Kalay, Tayfur Öztürk, Yener Kuru**
Affiliations : Department of Metallurgical and Materials Engineering, Middle East Technical University, Ankara 06800, Turkey

Resume : Perovskite type (La1-xSrx)CoO3-δ (LSC113) has been studied as one of the promising candidates for the cathode of intermediate temperature (500-700 ˚C) solid oxide fuel cells (IT-SOFCs); they show extraordinary exchange properties and the best mixed conduction among all aliovalent doped perovskites. Despite its advantages, the main problem in utilization of perovskite type LSC113 in SOFCs is surface strontium segregation and high thermal expansion coefficient, two effects both of which are detrimental at intermediate temperatures. Nonetheless, anomalously enhanced oxygen reduction kinetic around the (La1-xSrx)CoO3-δ/(La1-ySry)2CoO4+δ interface has been reported such that hetero interfacial surface oxygen exchange coefficient is 3-4 orders of magnitude higher than both phases. Such an enhancement in exchange property has potential to lower temperature of SOFC from intermediate to low temperature so long as the only source of the resistance is this highly improved surface exchange process. At such low temperatures, namely around 400 ˚C, thermal expansion and surface strontium segregation problems can be negligible. This approach presumes thin film cathodes. However, this scenario also necessitates extremely densified and vertically aligned hetero interface through this thin film. In this way, cathodes with vertical interfaces were obtained by PLD using only one target obtained via mechanically mixing separately synthesized powders with some success [1]. This study resulted in 1000 Ωcm2 at 400 ˚C and 0.21 atm P_(O_2 ), constituting the only attempt to yield high density of vertical interfaces. In the present work, (La0.8Sr0.2)CoO3-δ, (La0.5Sr0.5)CoO3-δ and (La0.5Sr0.5)2CoO4+δ (LSC214) powders were separately synthesized through low temperature solution based methods, ensuring the absence of any undesired phase [2]. Three oxide sputtering targets have been obtained from these powders by pressing them into 2-inch diameter pellets. The present work, then, attempts to obtain finely mixed interfaces via simultaneous sputtering by of LSC113 and LSC214 phases. This was achieved via a magnetron sputtering technique yielding thin film cathodes where the relative amounts of (La1-xSrx)CoO3-δ and (La0.5Sr0.5)2CoO4+δ phases varied. These variations were obtained by placing the substrates (GDC) in positions whose distance varied with respect to sputtering targets. In this way, more than ten different films were obtained for ORR measurement, each of which has its own interface creation as well as phase compositions. Thin film half cells having submicron thicknesses were then fabricated. These were then characterized via in-situ electrochemical impedance spectroscopy (EIS) with a frequency range between 1 MHz-10 mHz and 10 mV perturbation voltage amplitude. In-situ EIS measurements were conducted under different oxygen partial pressure and temperature combinations. The study aims to identify conditions giving the highest density of interfaces, the best associated ORR and hence the lowest possible ASR at 400 oC which is critical threshold for surface Sr segregation. Acknowledgement: The work reported in this study was supported by ERAFRICA FP7 Program: No. RE-037 HENERGY –TUBİTAK Project 114M128. ** deceased on 03.04.2016 References: [1] Ma, W., Kim, J. J., Tsvetkov, N., Daio, T., Kuru, Y., Cai, Z., et al. (2015). Vertically aligned nanocomposite La0.8Sr0.2CoO3/(La0.5Sr0.5)2CoO4 cathodes-electronic structure surface chemistry and oxygen reduction kinetics. Journal of Material Chemistry A (3), 207-219. [2] Torunoğlu Z. Ç., Demircan O., Kalay Y. E., Öztürk T. and Kuru Y., Utilization of Enhanced Oxygen Reduction Rate at Hetero Interface of(La0,8Sr0,2)CoO3-δ/(La0,5Sr0,5)2CoO4+δvia Dual Phase Synthesis. International Symposium on Materials for Energy Storage and Conversion Ankara, Turkey.Oral Presentation, September 7-9, 2015

Q.12.4
12:30 Lunch Break    
 
SESSION XIII : Isabella Nicotera
14:00
Authors : Marta Conti, Lucia Mazzapioda, Maria Assunta Navarra, Stefania Panero
Affiliations : Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro5, 00185 Rome, Italy

Resume : Large scale research efforts are still needed to meet the efficiency, durability and cost requirements for polymer electrolyte membrane (PEM) fuel cells (FCs). Developing electrolyte and electrode components that tolerate a wide range of operating conditions is particularly challenging. Desirable PEM must not only be highly proton conductive under hot and dry conditions, it should be thermally and dimensionally stable, impervious to fuels, as well as to electrons. At the same time, low noble metal-loaded catalysts with enhanced activity towards oxygen reduction and hydrogen oxidation are needed. We here propose a double-task strategy based on the use of highly acidic sulfated titanium oxide (S-TiO2) [1] as both additive in Nafion membranes and co-catalyst for the redox processes. Powerful investigation tools for the understanding of both micro- and macroscopic characteristics of the proposed materials will be presented. Proton conductivity of the hybrid organic-inorganic membranes, as well as the redox capability of S-TiO2-supported Pt-based catalysts, will be addressed together with performances of the proposed composite materials in working fuel cell prototypes. Particular care will be devoted to the functionality of the new PEMFC configuration under critical parameters, such as dry or low relative humidity conditions and temperatures up to 120 °C. [1] V. Allodi, S. Brutti, M. Giarola, M. Sgambetterra, M.A. Navarra, S. Panero, G. Mariotto, Polymers 2016, 8, 68. Acknowledgements: The results of this work have been obtained in the framework of the project titled “Polymer electrolyte membrane water electrolysers: innovative, cost-effective electrocatalysts with enhanced durability”, funded by Sapienza University of Rome (ATENEO 2015, prot. C26A15HE93).

Q.13.1
14:30
Authors : Stefania Marzorati, Massimo Lorenzi, Stephanie Fest-Santini, Maurizio Santini, Stefano P. Trasatti, Andrea Schievano, Pierangela Cristiani
Affiliations : Stefania Marzorati, Department of Agriculture and Environmental Science (DiSAA), Università degli Studi di Milano, Milano, ITALY; Massimo Lorenzi, School of Mathematics Computer Science and Engineering, City University London, UK; Stephanie Fest-Santini, Department of Management, Information and Production Engineering, Università degli Studi di Bergamo, Bergamo, ITALY; Maurizio Santini, Department of Engineering and Applied Sciences, Università degli Studi di Bergamo, Bergamo, ITALY; Stefano P. Trasatti, Department of Chemistry, Università degli Studi di Milano, Milano, ITALY; Andrea Schievano, Department of Agriculture and Environmental Science (DiSAA), Università degli Studi di Milano, Milano, ITALY, Pierangela Cristiani, RSE – Ricerca sul Sistema Energetico S.p.A., Milano, ITALY

Resume : Irreversible processes on the electrodes severely affect performances and full-scale application of microbial fuel cells (MFCs). Single Chamber MFCs are mainly limited by the cathodic oxygen reduction reaction, which is kinetically hindered, and further obstructed by fouling and deposition phenomena on the cathode. pH increases through the cathode, facilitating salts and inorganic forms precipitation. The study of biofouling and precipitation processes is therefore crucial for a deeper understanding and optimization over long term operation of MFCs. In this work, a carbon-based cathode, consisting of carbon cloth covered with a carbon microporous layer, was investigated. The electrochemical behaviour of the cathode has been analysed over time during the MFC life. X-ray microcomputed tomographies (microCTs) have been carried out at progressive stages of cathode inactivation. The technique provides cross-sectional images and 3D reconstruction of volumes. Lower grayscale values in the image indicate lower X-ray attenuation, (i.e., lower atomic density) thus allowing to distinguish biofilm from inorganic fouling on the basis of the value of the linear attenuation coefficient calculated voxel (3D pixel). MicroCT was combined with SEM and EDX techniques in order to recognise chemical species in each different layer of the cathode’s section. Results correlated the calcium and sodium carbonate deposits, in the inner and outer part of the cathode respectively, with the produced electric current over time. A specific microCT-related software quantified the time-dependent salts deposition, identifying a correlation between the decreasing performances and the increasing quantity of calcium carbonate deposits.

Q.13.2
15:00
Authors : Hamish A. Miller, Francesco Vizza and Dario R. Dekel
Affiliations : Hamish A. Miller and Francesco Vizza CNR-ICCOM ITALY; Dario R. Dekel, Technion - Israel Institute of Technology

Resume : One of the biggest obstacles to the diffusion of fuel cells is their cost, a large part of which is due to platinum (Pt) electrocatalysts. Complete removal of Pt is a difficult if not impossible task for proton exchange membrane fuel cells (PEM-FCs). The Anion Exchange Membrane Fuel Cell > (AEM-FC) has long been proposed as a solution as non-Pt metals may be employed. Despite this, few examples of Pt free AEM-FCs have been demonstrated with modest power output. The main obstacle preventing the realization of a high power density Pt free AEM-FC is sluggish hydrogen oxidation (HOR) kinetics of the anode catalyst. In this presentation we describe a Pt free AEM-FC that employs a mixed carbon-CeO2 supported palladium (Pd) anode catalyst that exhibits enhanced kinetics for the HOR. AEM-FC tests run on dry H2 and pure air show peak power densities of more than 500 mW cm-2. We have investigated the origin of this remarkable performance using cyclic voltammetry (CV), HR-TEM/STEM as well as XAS. This analysis shows the improvement is due to a strong interaction between Pd and CeO2. This talk describes a careful morphological analysis that attests to a fine dispersion of the Pd nanoparticles accumulated mostly on the ceria part of the catalyst. Such a structure helps to weaken the Pd-H bonds and assists in supplying OHad from oxophilic CeO2 to the Pd-Had (HOR reaction sites), thus accelerating the overall HOR.

Q.13.3
15:15
Authors : Stefano Trocino, Massimiliano Lo Faro, Sabrina C. Zignani, Giuseppe Monforte, Cristina Italiano, Antonio Vita, Antonino S. Aricò
Affiliations : CNR-ITAE, Via salita Santa Lucia sopra Contesse 5, 98126 Messina, Italy

Resume : The Solid Oxide Fuel Cells (SOFC) are electrochemical devices that may find application in stationary as well oversize vehicles such as aircraft or ships. Accordingly, the SOFC systems must demonstrate reliability towards the utilization of conventional heavy hydrocarbon fuels such as the diesel especially for on-board applications. The SOFC has already demonstrated a level of maturity as regards the manufacture of cells having Ni-based anode, stack, and systems. Nowadays, this type of technology is quite far from its use in real environmental conditions in which H2 is not available, although the main manufacture companies have forecasted that the global SOFC market is being to grow of 10.3 % over the period 2014-2019 as reported by TechNavio. Therefore, the main possibility for a rapid penetration of such technology into the market of generators for distributed energy is the utilization of a chemical processor coupled to the SOFC. Diesel is a complex mixture of heavy hydrocarbons; therefore, for a good comprehension of the processes occurring during the transformation of a fuel to energy, a pure and single hydrocarbon molecule simulating a complex fuel is necessary. In these terms, the use of n-dodecane for tests concerning the next use of diesel into the SOFC can give significant information. In this work we explored the reliability and feasibility of a coupled system based on a chemical processor and a SOFC operating at 800 °C. Furthermore, we will report on the development of a 500 Wel system based on a SOFC stack coupled with a reformer of n-dodecane.

Q.13.4
15:30 Coffe Break    
 
SESSION XIV : Vincenzo Baglio
16:00
Authors : Isabella Nicotera, Cataldo Simari, Luigi Coppola, Cesare Oliviero Rossi, Giuseppe A. Ranieri
Affiliations : Department of Chemistry and Chemical Technologies, University of Calabria, 87036 Rende (CS), Italy

Resume : Hydrophilic 2D platelike layers in polymeric matrix is of great interest due to significant gains in thermal stability, mechanical and barrier properties of the resulting nanocomposites. Lately, a series of novel nanostructured organo-modified layered materials based on graphene oxide (GO) and on silicates (clays and LDH) were synthesized, to be homogeneously dispersed into Nafion polymer. The membrane preparation procedure, as well as the exploitation of their large surface area, to be properly functionalized and to interact with the polymer, are the key points to prepare advanced nanocomposites for PEMFC applications. For instance, such materials can modulate the nature of water confined in the nanosized ionic channels of Nafion, and, as a result, hybrid membranes have showed high proton mobility and water retention at temperature >100 °C. Furthermore, the barrier properties of these layered materials was valuated to reduce the methanol crossover (critical issue in the DMFCs), through obstruction effect by increasing of the tortuosity of the fuel diffusion path. NMR spectroscopy is crucial for the molecular dynamics investigation, and was widely used to study the proton transport mechanism within the membranes through direct measurement of the self-diffusion coefficients (PFG technique) and the spin-lattice relaxation times (T1). The aim was to provide a general description of the water management (and methanol) inside the systems and of the effects of the fillers.

Q.14.1
16:30
Authors : Andrea Perego 1-2, Andrea Monti 2, Andrea Bisello 2, Andrea Casalegno 2, Fabio Di Fonzo 1
Affiliations : 1: Center for Nano Science and Technology @Polimi, via G.Pascoli 70/3, 20133 Milano, Italy 2: Dipartimento di Energia, Politecnico di Milano, Via Ponzio, 20133 Milano, Italy

Resume : One of the critical issues in Direct Methanol Fuel Cells (DMFC) technology is the crossover of liquid methanol from anode to cathode side. Due to its high affinity with water, methanol crosses the Nafion® membrane reaching the cathode, where it oxidizes in presence of oxygen without electron injection in the external circuit causing severe energy loss. One possible solution presented is using palladium barriers, due to its remarkable proton conduction properties. In 2014, Casalegno et.al developed a palladium barrier deposited directly on the Nafion 115® membrane by PLD [Int. J. Hydrogen En. 2014, 39(6), 2801-2811]. Although the protonic resistance was increased, the cell efficiency improved due to a strong decrease in methanol crossover. In this work, we present a compact Pd barrier deposited on a thinner Nafion XL® membrane (25.7µm) by means of DC sputtering. The choice of a 4 times thinner membrane, compared to state of art Nafion 115® is to compensate the decrease in proton conductivity due to the presence of the palladium. Palladium barriers are sandwiched between two commercial DMFC electrodes and tested in fuel cell configuration. Performance curves and spectroscopy analysis are performed, while membrane resistance and methanol crossover are constantly monitored. With an efficient way to block the crossover, it could be possible to improve the cell performances along with the efficiency, filling partially the gap to large-scale commercialization of this technology.

Q.14.2
16:45
Authors : Fabio V. Matera; Irene Gatto; Ada Saccà
Affiliations : CNR-ITAE

Resume : Hydrogen compression by means of an electrochemical cell (EHC) is a very efficient and innovative technology for high pressure hydrogen storage, meanwhile efficient small size gas compressors able to withstand low power Polymer Electrolyte Fuel Cell (PEFC) stack conditions are hard to find on the market. They are also quite inefficient, noisy, produce undesired vibrations and pulsation. Thanks to its modularity, simplicity and the use of most of the fuel cell technology parts and design, the EHC (Electrochemical Hydrogen Compressor) can be used also for hydrogen recirculation within a Polymer Electrolyte Fuel Cell (PEFC) stack. In such a case, the pressure drop is usually very low (0,5-1 bar) while operative conditions (pressure, flow, temperature and relative humidity) are mostly influenced by the stack. In this work, the behaviour of two different membranes (a reference Nafion NR212 and a in-house manufactured composite Ni-TiOx) has been studied to optimise the operation at low pressure and give design input for an integrated stack-EHC unit. The experimental results show that the composite membrane gives better performance than the thinner Nafion NR212 thanks to its water retention properties, also giving evidence that the largest energy loss is due to the membrane resistance. The best operative conditions are then to operate at low current density, increasing the active area of the MEA (membrane and electrode assembly) and the overall EHC size.

Q.14.3
17:00
Authors : B. Aghabarari1, N. Nezafati1, M. Roca-Ayats2, M. J. Lázaro3, M. V. Martínez-Huerta2
Affiliations : 1 Department of Nanotechnology and Advanced Material, MERC, Tehran, PO box 14155‑4777, Iran 2 Institute of Catalysis and Petrochemistry, CSIC. Marie Curie 2. E28049 Madrid, Spain 3 Institute of Carbochemistry, CSIC. Miguel Luesma Castán 4, E50018 Zaragoza, Spain

Resume : Chitosan is a naturally abundant, low-cost and renewable polymer, which has excellent properties such as, biodegradability, non-toxicity and excellent stability. This biopolymer has good complexing ability due to the presence of –OH and –NH2 groups on the chain. During the last few years, nitrogen-doped carbon seems to be the most suitable oxygen reduction reaction (ORR) active material in the cathode catalyst for low temperature fuel cells. Recently, our research group have shown that hybrid chitosan derivative–carbon black used as support for Pt nanoparticles can improve the activity toward the ORR [1]. Herein, we describe the preparation and characterization of new bio-nanocomposite formed by chitosan with graphene and heteropolyacids for ORR in alkaline media. Physicochemical characterization of catalyst was performed by FTIRS, TGA, Raman, XRD, XPS, TEM and ICP-OES. Activity toward ORR was carried out in a three-electrode electrochemical cell using a rotating ring-disc electrode (RRDE). Acknowledgements This work was supported by the Spanish Government under the MINECO project ENE2014-52158-C2-1R (co-funded by FEDER), Spanish National Research Council COOPB20202 and MERC project 721394002. M.R.A acknowledges the FPU-2012 program for financial support. References 1. B. Aghabarari M. V. Martinez-Huerta, M. Ghiaci, J. L. G. Fierro and M. A. Peña, RSC Advances, 2013, 3, 5378

Q.14.4
17:15
Authors : Jiseon You, Richard J. Preen, Larry Bull, John Greenman, Ioannis Ieropoulos
Affiliations : Bristol BioEnergy Centre, UWE, Bristol, UK; Department of Computer Science and Creative Technologies, UWE, Bristol, UK; Department of Computer Science and Creative Technologies, UWE, Bristol, UK; Bristol BioEnergy Centre, UWE, Bristol, UK; Bristol BioEnergy Centre, UWE, Bristol, UK

Resume : For practical applications of the MFC technology, the design as well as the processes of manufacturing and assembly, should be optimised for the specific target use. Another rising technology, additive manufacturing (3D printing), can contribute significantly to this approach by offering a high degree of design freedom. In this study, we investigated the use of commercially available 3D printable polymer materials as the MFC membrane and anode. The best performing membrane material, Gel-Lay, produced a maximum power of 240 ± 11 µW, which was 1.4 fold higher than the control CEM with PMAX of 177 ± 29 µW. Peak power values of Gel-Lay (133.8 – 184.6 µW) during fed-batch cycles were also higher than the control (133.4 – 160.5 µW). In terms of material cost, the tested membranes were slightly higher than the control CEM, primarily due to the small purchased quantity. Finally, the first 3D printable polymer anode, a conductive PLA material, showed significant potential as a low-cost and easy to build MFC anode, producing a stable level of power output, despite poor conductivity and relatively small surface area per unit volume. These results demonstrate the practicality of monolithic MFC fabrication with individually optimised components at relatively low cost.

Q.14.5

Symposium organizers
Ana C. TAVARESINRS

1650 Boulevard Lionel-Boulet Varennes (Quebec) J3X1S2 Canada

ana.tavares@emt.inrs.ca
Claudia D’URSOCNR-ITAE

Via Salita Santa Lucia Sopra Contesse, 5-98126 Messina, Italy

durso@itae.cnr.it
Enrico TRAVERSAUniversita’ Di Roma Tor Vergata

Via Della Ricerca Scientifica, Roma, Italy

traversa@uniroma2.it
Luis Gerardo ARRIAGA HURTADOCIDETEQ-S.C.

Sanfandila Pedro Escobedo QRO C.P. 76703, Mexico

larriaga@cideteq.mx
Maria Jesus LAZAROICB-CSIC

Avda Illustracion n 35 casa 150, 50.012 Zaragoza, Spain

mlazaro@icb.csic.es