MEMBRANE ELECTRODE ASSEMBLY AND SOLID POLYMER ELECTROLYTE FUEL CELL

摘要

[Problem] To provide a membrane and electrode assembly comprising a catalyst layer that improves water holding properties and exhibits high power generation characteristics even in low humidified conditions without inhibiting the diffusibility of reaction gas, the removal of the water generated by the electrode reaction, etc. and its manufacturing method. [Solution] The membrane and electrode assembly produced by sandwiching a polymer electrolyte membrane between a pair of catalyst layers is provided, in which the catalyst layer comprises a polymer electrolyte and particles carrying a catalyst material, and in which the volume of fine pores having a diameter of 1.0 µm or smaller in terms of cylinder approximation for fine pores evaluated by the mercury intruction method in the catalyst layer is increased toward the polymer electrolyte membrane (the inside) from the surface of the catalyst layer (the outside).