Abstract: The effect of heat treatment on catalytic activity of a PtRu/C electrocatalyst synthesized by the polyol method was investigated by thermogravimetry, on-line mass spectroscopy, X-ray diffraction,?and transmission electron microscopy. The results indicate that abundant species adsorbs on the electrocatalyst surface, which can be effectively removed by heat-treating at 200 ^oC under inert atmosphere for 2 h. The particle size of the electrocatalyst increases slightly after heat treatment, but the particles remain good dispersion on the carbon support. Electrochemical and direct methanol fuel cell single cell test results indicate that the catalytic activity of PtRu/C for methanol electrooxidation is greatly improved by the heat treatment process.

Key words: platinum, ruthenium, heat treatment, polyol method, methanol electrooxidation, direct methanol fuel cell