SURICAT

Proton Exchange Membrane Fuel Cells (PEMFC) are ecologically clean and efficient energy converters, whose power ranges allow their utilization in different domains, mobile, transport and stationary applications. Nevertheless their development in a large scale needs further improvements, specifically regarding lifetime. PEMFC lifetime is particularly linked to the cathode carbonaceous support degradation. To relieve such a major problem, SURICAT aims at developing new catalyst supports, without any carbon, based on metal oxides. Such supports will have to fulfill at least 4 essential criteria: electronic conductivity, possible synthesis of electrochemically active electrocatalyst, corrosion resistance in PEMFC operating conditions and adapted morphology for electrode shapping and fuel cell operation. Two oxides have been selected on the basis of promising preliminary works: titanium dioxide (TiO2) and tin dioxide (SnO2). Their electronic conductivity will be increased by doping (V, NB or Ta) or post-treatment favoring the creation of oxygen vacancies. They will be synthesized following different synthesis routes in order to evaluate the influence of the morphology (spherical particles vs. fibers vs. aerogels) on the catalyst deposition and electrode preparation, on the charge carriers’ mobility as well as on mass transfers through the catalytic layer. A selection process based on the four selected criteria (conductivity, electrochemical activity, corrosion resistance and morphology) will be followed all along the elaboration process (support matrix, electrocatalysts, catalytic layer), through a panel of physicochemical and electrochemical characterizations. The selected metal oxides will then be utilized to prepare Membrane-Electrodes Assemblies (MEAs), characterized on single cell test bench in order to evaluate their performances and, thanks to accelerated ageing tests, the durability of the new supports. The performances of the electrocatalysts composed of metal oxides supported Pt nanoparticles (Pt/MOx) will be compared to those of conventional high specific surface area carbon blacks supported electrocatalysts (typically TKK TEC10E40E). Finally, new promising supports, showing better performances (power density and lifetime) than commercially available carbon blacks, will integrated and evaluated in small portable devices.