Physicochemical characterization of commercial Pt/C and PtRu/C catalysts was carried out by X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy. Comparative studies of methanol electrooxidation on carbon supported Pt and PtRu catalysts in acid solution were performed by means of an electrochemical method. The experimental results showed that PtRu/C not only had a higher electrocatalytic activity for the electrocatalytic oxidation of methanol than Pt/C, but also for the electrocatalytic oxidation of adsorbed CO. Alloy formation of Ru with Pt modified not only the characteristics of H2 adsorption on the surface of catalyst but also the characteristics of CO adsorption on the sur face of catalyst. The interaction of CHaOH with Ru was a temperature-activated process requiring elevated temperature.