Patent ID: 8546042

Claim:
A membrane electrode assembly comprising: an oxygen electrode including a catalyst layer for reducing oxygen, a fuel electrode including a catalyst layer for oxidizing fuel, and a polymer electrolyte membrane interposed between the oxygen electrode and the fuel electrode, wherein at least one of the catalyst layer of the oxygen electrode and the catalyst layer of the fuel electrode includes: carbon supporting a metal catalyst containing a platinum group element; a proton conductive polymer electrolyte; and at least one selected from (a) a complex-forming agent having a ligand that forms coordinate bonds with ions of the platinum group element and forms a complex, the ligand containing oxygen as a coordinating atom, (b) a complex of the platinum group element, a ligand of the complex containing oxygen as a coordinating atom, and (c) carbon that does not support the metal catalyst, the carbon having a BET specific surface area of 100 m 2 /g or greater, an R value of Raman spectrum of 0.1 or greater and a lattice spacing d 002 between (002) planes of 0.35 nm or less.