MEMBRANE CATALYST LAYER ASSEMBLY, MEMBRANE ELECTRODE ASSEMBLY, AND POLYMER ELECTROLYTE FUEL CELL

摘要

An object of the present invention is to provide a catalyst-coated membrane suitable for achieving a polymer electrolyte fuel cell that sufficiently prevents a decrease in the initial characteristics and also exhibits sufficient cell performance for a long period of time and has excellent durability. In at least the cathode catalyst layer, the ratio (W P /W Cat-C ) of the weight of the polymer electrolyte (W P ) to the weight of the catalyst-carrying carbon (W Cat-C ) is decreased from an innermost layer positioned closest to the polymer electrolyte membrane toward an outermost layer positioned farthest from the polymer electrolyte membrane. The ratio (W P /W Cat-C ) in the innermost layer is 0.8 to 3.0, and the ratio (W P /W Cat-C ) in the outermost layer is 0.2 to 0.6.