Patent ID: 7132191

Claim:
A device comprising a membrane electrode assembly wherein said membrane electrode assembly comprises: a cathode catalyst layer having a first set of edges; an anode catalyst layer having a second set of edges; a solid polymer electrolyte provided between said cathode and anode catalyst layers, said solid polymer having an ionom 1 er and a third set of edges, wherein said anode catalyst layer has a surface area in contact with said ionomer which is less than a surface area of said cathode catalyst layer in contact with said ionomer, and said first set of edges of said cathode catalyst layer are closer in proximity than said second set of edges of said anode catalyst layer to said third set of edges of said electrolyte; and first and second diffusion layers, wherein the surface areas of said catalyst layers in contact with said ionomer are sized entirely by gaskets interposed between said electrolyte and said diffusion layers.