Porous Metal Support for Gas Diffusion Electrode of PEFCs

Abstract

Carbon support, widely used for electrocatalysts of polymer electrolyte fuel cells (PEFCs), tends to corrode under high potential conditions. Therefore, metal oxides stable even under PEFC conditions have been proposed as alternative support materials. Here in this study, porous metals are applied to catalyst support materials, where stable metal oxide is formed on the outermost surface. As model materials, metallic titanium sintered sheets are examined, as their oxides (TiO2) are expected to have high durability under PEFC conditions. Porous metal sheets can also act as gas diffusion layer (GDL). Such unique structure, in which both the electrocatalyst layer and the GDL are integrated, has a potential to simplify the MEA structure and possibly fabrication processes. Such catalyst-integrated electrodes are prepared, and their microstructure and electrochemical properties are evaluated.