a gas reaction fuel cell may be provided with a solid polymer electrolyte membrane . porous gas diffusion electrodes are formed of carbon particles supporting a catalyst which is effective to enhance the gas reactions . the carbon particles define interstitial spaces exposing the catalyst on a large surface area of the carbon particles . a proton conducting material , such as a perfluorocarbon copolymer or ruthenium dioxide contacts the surface areas of the carbon particles adjacent the interstitial spaces . the proton conducting material enables protons produced by the gas reactions adjacent the supported catalyst to have a conductive path with the electrolyte membrane . the carbon particles provide a conductive path for electrons . a suitable electrode may be formed by dispersing a solution containing a proton conducting material over the surface of the electrode in a manner effective to coat carbon surfaces adjacent the interstitial spaces without impeding gas flow into the interstitial spaces .