MEASURING METHOD OF THE SPECIFIC SURFACE AREA AVAILABLE FOR REACTION OF NOBLE METAL CATALYST IN THE ELECTRODE OF POLYMER ELECTROLYTE MEMBRANE FUEL CELL AND A DESIGNING OF CATALYSTLAYER FOR THE ELECTRODE OF THE SAME FUEL CELL

摘要

A measuring method for determining the specific surface area available for reaction of a noble metal catalyst of an electrode for use in a polymer electrolyte membrane fuel cell. The method includes measuring the total specific surface area of the noble metal catalyst and the specific surface area of the noble metal catalyst mixed with a polymer electrolyte by detecting the adsorption amounts of carbon monoxide upon exposure to carbon monoxide after reduction in hydrogen, and subtracting the latter from the former. Also provided is an electrode material for use in a polymer electrolyte membrane fuel cell having excellent polarization characteristics by controlling the utilization of a noble metal catalyst determined from the total specific surface area and specific surface area available for reaction of the noble metalcatalyst. The electrode material includes a noble metal catalyst powder and a polymer electrolyte, wherein the utilization ratio of the noble metal catalyst is at least 40% of the saturation value of the utilization of the noble metal catalyst powder.