Ce-Doped La2O3 based catalyst for the oxidative coupling of methane

The effect of ceria was studied on the oxidative coupling of methane (OCM) with Ce-doped La2O3 in a La:Ce molar ratio of 75:25 using two preparation methods. The characterisation techniques used were XRD and XPS. The results revealed high concentration of oxygen vacancies. Different types of ions (Ce3+ + Ce4+) were detected. More surface Ce3+ and higher ratio [(O-2(2-) + O-)/O2-] were obtained in the oxide synthesised by the solvothermal method, affecting the OCM reaction in terms of higher C-2 hydrocarbons selectivity. This was ascribed to the higher relative amount of O- species on the catalyst surface. (C) 2013 Published by Elsevier B.V.