The state of Rh during the partial oxidation of methane into synthesis gas

The partial oxidation of methane to synthesis gas over an alpha-Al2O3- and gamma-Al2O3-supported Rh catalyst has been studied at atmospheric pressure using in situ DRIFTS between 823 and 973 K. A surface intermediate species with IR band at 2000 cm(-1), correlating with the CO formation, was observe d during the partial oxidation. DRIFT spectra of adsorbed CO at 323 K were used to study the state of Rh during the partial oxidation. The state of Rh at 973 K is proposed to be a matrix of metallic rhodium with clusters of p artially reduced oxide phase with isolated Rh+ atoms dispersed on the suppo rt. Rh oxide with Rh+ cations is the state of Rh during partial oxidation o f methane at 823 K.