Abstract: Rare earth oxides have been used as catalysts for the oxidative coupling of methane,La₂O₃ and Sm₂O₃ showed higher C₂ selectivity. The mixture of La₂O₃ and alkaline earthoxide was found to be effective for oxidative coupling, among them binary oxide of La-Ba(1:1) gave the highest C₂ yield, up to 20%. It is suggested that there could be a combination effect of this binary system due to the structural influences, such as the specific sur-face area. Based on the temperature dependence of the products distribution, a mechanism ofthe reaction was proposed.

Key words: methane, oxidative coupling, catalyst, rare earth oxide