Patent ID: 8906574

Claim:
A fuel cell membrane-electrode assembly comprising: an electrolyte membrane; a fuel electrode provided at one surface side of the electrolyte membrane; and an oxidant electrode provided at another surface side of the electrolyte membrane, wherein at least one of the fuel electrode and the oxidant electrode has a non-supported-catalyst containing catalyst layer that contains: a metal catalyst nanoparticle of 0.3 nm to 100 nm in primary particle diameter that is not supported on a support, and an electrochemically active surface area of the metal catalyst nanoparticle is 10 m 2 /g to 150 m 2 /g, and a layer thickness of the non-supported-catalyst containing catalyst layer is less than or equal to 10 μm, wherein the metal catalyst nanoparticle is highly dispersed and restrained from aggregating, and wherein the non-supported-catalyst containing catalyst layer further contains a carbon particle that is a water-repellent particle and that has surface area of 5 to 50 m 2 /g.