Patent ID: 7824786
Filing Date: 2010-11-02
Classification: H01M,Y02E

Abstract:
1. A membrane electrode assembly comprising an anode catalyst layer, a cathode catalyst layer, an anode and a cathode each made of an electrode substrate, and a polymer electrolyte membrane sandwiched between the anode and the cathode, the membrane electrode assembly satisfying the following expression: wherein the reaction resistance at 20° C. is represented by Rr (Ω·cm the polymer electrolyte membrane is a hydrocarbon-based polymer electrolyte membrane; the anode catalyst layer has a thickness of 1 μm or more and 150 μm or less and a platinum content of 0.1 mg/cm the cathode catalyst layer has a thickness of 1 μm or more and 500 μm or less and a platinum content of 0.1 mg/cm the anode catalyst layer has an amount of platinum per micrometer of thickness of 0.07 mg/cm the platinum in the anode catalyst layer exists in a first state and a second state, platinum being carried on a surface of a carbonaceous material in the first state and platinum being mixed into the anode catalyst layer without being carried on the carbonaceous material in the second state; and the cathode catalyst layer has an amount of platinum per micrometer of thickness of 0.15 mg/cm