Patent ID: 8029945

Claim:
A method of preparing a metal catalyst comprising a conductive catalyst material and a coating layer formed of a water repellent material on a surface of the conductive catalyst material, the method comprising: obtaining a water repellent material solution by dissolving the water repellent material in a first solvent; separately, obtaining a conductive catalyst mixture by mixing the conductive catalyst material and the first solvent; mixing the water repellent material solution and the conductive catalyst mixture; casting the mixed water repellent material solution and conductive catalyst mixture onto a supporter and drying the cast result to obtain the metal catalyst comprising the conductive catalyst material and a coating layer of the water repellent material formed on a surface of the conductive catalyst material; separating the metal catalyst in a solid state from the supporter; and pulverizing and sieving the separated metal catalyst, wherein the first solvent comprises at least one material selected from the group consisting of hydrofluoropolyester, N-methylpyrrolidone, dimethylacetamide, dimethylformamide, and trifluoroacetic acid; wherein the water repellent material comprises at least one material selected from the group consisting of 2,2-bistrifluoromethyl-4,5-difluoro-1,3-dioxol tetrafluoroethylene copolymer, polytetrafluoroethylene, fluorinated ethylene propylene, polyvinylidenefluoride, and a fluoro-polymer sold under the trademark name FLUOROSARF.