Suppressed formation of CO2 and H2O in the oxidative coupling of methane over La2O3/MgO catalyst by surface modification

Oxidative coupling of methane (OCM) is a promising way to convert methane into C-2 hydrocarbons. However. CO2 and H2O are by-products of the reaction To utilize the higher activity of lanthanum oxide and save its usage. MgO supported La2O3 catalyst was prepared Surface modification of the catalyst with nitric acid was made to suppress the formation of the by-products Experimental results indicated that the addition of nitric acid increased the surface oxygen species with binding energy of ca 531 7 eV and at the same time reduced the pore volume of the catalyst These effects of nitric acid finally led to the increase of C-2 selectivity and the decrease of the by-products formation Hydrogen selectivity was found about 14%-18% over the catalysts adopted in this work