COMMON FEATURES OF OXIDATIVE COUPLING OF METHANE COFEED CATALYSTS

Although research on the oxidative coupling of methane has attracted significant attention recently, the determination of active and selective catalyst compositions appears to have little theoretical foundation at the present time. The examination of a number of these catalysts has enabled us to conclude that most, if not all, of these active and selective catalysts are composed of basic, irreducible surface oxides which form stable surface carbonate species. These catalysts are also high-temperature p-type semiconductors under normal operating oxygen partial pressures. Based on these observations alkaline earth and rare earth doped thoria compounds are expected to be catalysts for this reaction.