PEFCs Using Metallic Ti and Sn Electrocatalyst Supports

Carbon supports, which are widely used for electrocatalysts of polymer electrolyte fuel cells (PEFCs), can be electrochemically oxidized and corroded under the high potential conditions of PEFCs. Therefore, metal oxides, which are stable under PEFC conditions, have been proposed as alternative support materials. In this study, metals with porous structure, forming stable metal oxides on the outermost surface, are applied to electrocatalyst supports. Metallic titanium and metallic tin are examined, as their oxides (TiO2 and SnO2) are highly durable even under PEFC conditions. In addition, by tailoring porous structures, their metallic supports have the potential to function as both electrocatalyst layer and gas diffusion layer (GDL), simplifying the MEA structure and possibly fabrication processes. Such catalyst-integrated electrodes are prepared, and their electrochemical properties are evaluated.