Patent ID: 8399144

Claim:
A membrane-electrode assembly for a direct oxidation fuel cell, comprising an electrolyte membrane, and an anode and a cathode sandwiching said electrolyte membrane, wherein: the cathode comprises a catalyst layer in contact with the electrolyte membrane and a diffusion layer sandwiching the catalyst layer with the electrolyte membrane, the catalyst layer has a volume V 1 and contains pores having a volume v 1 , pores having a controllable volume v 2 are present between the electrolyte membrane and the catalyst layer, pores having a controllable volume v 3 are present between the diffusion layer and the catalyst layer, where (v 1 +v 2 +v 3 )/(V 1 +v 1 +v 2 +v 3 ) is 2 to 20%, the amount of a catalyst in the catalyst layer per unit area of a projected shape of the catalyst layer is 0.6 to 1.6 mg/cm 2 , and the thickness of the catalyst layer is 20 to 70 μm.