The oxidation of ethanol was studied on Pt-Ru and Pt-Mo electrocatalysts, supported on high-surface-area carbon, prepared by reduction with formic acid. The catalysts, containing up to 40 atom % of the second metal, were characterized by X-ray diffraction, energy-dispersive X-ray analyses, and X-ray absorption experiments. The oxidation of ethanol was studied by cyclic voltammetry, chronoamperometry, and differential electrochemical mass spectroscopy experiments. Within the conditions used in this work, it was found that the activity for ethanol oxidation increased with the contents of the second metal and with the concentration of ethanol. © 2002 The Electrochemical Society. All rights reserved.