Measuring specific surface area of catalyst available for reaction in fuel cells

摘要

Measuring the specific surface area (SSA) available for reaction of a noble metal catalyst of an electrode material powder for a polymer electrolyte membrane fuel cell (PEMFC) comprises: (a) reducing a first electrode material powder comprising a noble metal catalyst on a powdered carbon carrier; (b) reducing a second electrode material powder comprising a noble metal catalyst covered with polymer electrolyte (PE) on a powdered carbon carrier; (c) exposing the first electrode powder to carbon monoxide and measuring the total SSA of the noble metal catalyst from the amount of carbon monoxide adsorbed; (d) exposing the second electrode powder to carbon monoxide and measuring the SSA of the catalyst from carbon monoxide adsorption as above; and (e) obtaining the available SSA by subtracting the value obtained in step (d) from the value obtained in step (c). Also claimed is an electrode for a PEMFC having an electrode material comprising: (i) a noble metal catalyst powder; and (ii) a polymer electrolyte; such that the utilisation ratio of the catalyst is at least 40% of the saturation utilisation value.