Characterization of Pd/C and Cu catalysts for the oxidation of methane to a methanol derivative

Abstract

Carbon-supported Pd catalysts with a copper compound for the oxidation of methane to a methanol derivative, CF3COOCH3, in the presence of CO and O-2 were characterized. The bulk structure and chemical environment of palladium and copper were determined by XRD and XAFS, respectively. In this reaction system, the nature of cocatalyst, the presence of Cl-, and the solvent composition changed the structure of the palladium species and affected the yield of CF3COOCH3. In the presence of a copper compound and Cl-, the metallic palladium can be partly oxidized into Pd(II) species, which resulted in higher yields of CF3COOCH3. For the active catalyst system, the copper compound was present as CuCl, Pd(II) species coordinated with Cl- appeared to be essential for the selective activation of methane and the metallic palladium for the in situ generation of H2O2 from CO, H2O, and O-2. (C) 2000 Academic Press