Catalytic wet air oxidation of gasoline oxygenates (ETBE and TAME) were carried out using Rh/gamma-Al2O3, Rh/gamma-Al2O3-CeO2 catalysts in a Parr reactor at 100, 120 and 150 degrees C using oxygen as oxidant source at 10 bar of pressure. Aqueous solutions of ETBE and TAME were prepared using the quantities necessary to obtain 227 ppm. The quantity of catalyst used was 1 g/L. Cerium emphasizes the oxidative capacity of the rhodium catalysts at 100 degrees C explained by the formation of rhodium oxide sites (Rh2O3) at the surface, detected by TPR and XPS techniques. This capacity has been observed by the high CO2 selectivity due to the support-metal interaction by the formation of Ce4+-O2--M+ bond which prevents the formation of carboxylic acids intermediate as acetic, the most refractory acid found. (C) 2008 Elsevier B.V. All rights reserved.