This work studied the effect of the nature of the metal on the performance of Co/CeO2, Pd/CeO2 and Pt/CeO2 catalysts in the partial oxidation of ethanol. Infrared spectroscopy of adsorbed ethanol and temperature programmed desorption of ethanol were performed in order to establish the reaction mechanism. Catalytic experiments revealed that the product distribution is strongly affected by the nature of the metal. Acetaldehyde was practically the only product formed on a Co/Ce\O-2 catalyst while methane was also produced on Pt/CeO2 and Pd/CeO2 catalysts. These results were explained through a reaction mechanism proposed by the characterization techniques.(c) 2005 Elsevier B.V. All rights reserved.