Method of producing conducting polymer-transition metal electro-catalyst composition and electrodes for fuel cells

Abstract

A method of producing an electro-catalyst composition for use as an electrode, gas diffusion layer-supported electrode, catalyst-coated solid electrolyte layer, and membrane-electrode assembly in a proton exchange membrane (PEM) type fuel cell. The method comprises: (a) preparing a proton- and electron-conducting polymer having an electronic conductivity no less than 10−3 S/cm and a proton conductivity no less than 10−4 S/cm; (b) mixing and reacting this conducting polymer with a plurality of transition metal coordination complexes to produce the desired electro-catalyst composition having at least one heteroatom per backbone monomer unit thereof and a plurality of neutral transition metal atoms covalently bonded to at least a portion of the heteroatoms. The step of reacting preferably comprises (b1) complexing the conducting polymer with the plurality of transition metal coordination complexes to form a polymer-transition metal complex and (b2) reducing the polymer-transition metal complex to place the transition metal in a neutral oxidation state. A hydrogen-oxygen PEM fuel cell or a direct methanol fuel cell (DMFC) featuring such an electro-catalyst composition in a thin-film electrode exhibits a superior current-voltage response.

Dependencies are inferred from the claim text.