The partial oxidation of CH4 over Rh/Al2O3 was studied by means of temporal analysis of products (TAP). CH4 was found to adsorb dissociatively on reduced metal sites. Oxygen preadsorption decreases the methane adsorption rate. The oxidation products under oxidative conditions are CO2 and H2O. The selectivity towards CO and H-2 rises to almost 100% as the conditions become more reductive. Water adsorbed on the support acts as an oxygen source through the inverse spillover of water or hydroxyl onto the Rh particles. A reaction scheme for the partial oxidation of methane is presented and the elementary reactions that give overall steam reforming, CO2 reforming, and water-gas shift are discussed.