Methane Coupling over Terbium Oxide Catalysts Using Carbon Dioxide as Oxidant.

Abstract

Conversion of methane and carbon dioxide into ethane and ethylene (C2 hydrocarbons) has been performed over terbium (Tb) oxide catalysts. Effectiveness of catalyst is influenced by precursor of the oxide; a Tb oxide prepared from the nitrate shows the highest C2 yield, whereas, an oxide from the oxalate gives the highest C2 selectivity. Since CO yield increases with increasing specific surface area of the Tb oxide, attributed to the successive oxidation of C2 hydrocarbons formed from CH4, lower specific surface area is favored for formation of C2. Examining the effects of reaction conditions on the performance of the catalyst from Tb nitrate, it was found that the highest C2 yield and selectivity are obtained at 1173K and 1073K, respectively, and higher C2 selectivity was observed at higher partial pressure of CH4.