Conversion of methane with carbon dioxide into C2 hydrocarbons over metal oxides Original Research Article

Conversion of methane with carbon dioxide has been performed over seventeen metal oxides using a flow reaction system at 1123 K. The conversion ratio of carbon dioxide to methane is approximately two in most cases. Ethane and ethene (C2 hydrocarbons) are formed over many oxides, and C2 yield is higher over yttrium and manganese oxides. Rare earth catalysts such as yttrium, lanthanum, and samarium show higher C2 selectivities of about 30%. C2 selectivity is almost unchanged over yttrium and zirconium oxides during reaction while it decreases over samarium oxide. X-ray diffraction analysis reveals that some oxides such as manganese and iron oxides are reduced during reaction. The reaction mechanism for C2 formation is discussed in terms of both adsorbed oxygen species dissociated from carbon dioxide and the lattice oxygen in metal oxides.