MEMBRANE ELECTRODE ASSEMBLY AND FUEL CELL

摘要

Disclosed is a membrane electrode assembly (50) comprising a solid polymer electrolyte membrane (20), an anode (22) and a cathode (24). The cathode (24) comprises a laminate composed of a catalyst layer (30) and a gas diffusion layer (32). The catalyst layer (30) comprises carbon particles each having platinum and cobalt carried thereon and an ionic conductor. In the catalyst layer (30), the ratio of P1 (ml/g) to P2 (ml/g) (i.e., a P2/P1 ratio) of 3.8 to 8.3 inclusive, wherein P1 represents a fine pore volume (mg/l) of fine pores having a first fine pore size of not less than 0.01 µm and less than 1 µm per 1 g of the catalyst layer and P2 represents a fine pore volume (ml/g) of fine pores having a second fine pore size of not less than 0.1 µm and less than 1 µm per 1 g of the catalyst layer.