Reaction steps in the oxidation of CH4 to CO and H2 over a Rh(1 wt%)/gamma-Al2O3 catalyst were studied using in situ DRIFTS at 973 K and 0.1 MPa. Product distribution and the resulting absorption band intensities of the respective adsorbates were strongly influenced by oxygen coverage and carbon deposits on the surface. CH4 is dehydrogenated to carbon deposits and H2 and is simultaneously oxidized to CO2 and H2O. OH surface groups in the support are involved in the CH(x) conversion to CO via reforming reaction. The reaction of surface carbon with CO2 was assumed to contribute to CO formation. Formate is a by-product of the reaction.