Surface composition and reactivity of lithium-doped magnesium oxide catalysts for oxidative coupling of methane

Lithium-doped magnesium oxide catalysts for oxidative coupling of methane with lithium loadings ranging from 0.02 to 10 wt% have been studied using both kinetic and XPS measurements. A correlation between CH, conversion and the concentration of surface species corresponding to an O(1s) XPS peak at 533.0 eV has been obtained. These active species were assigned to Li+O− centers formed by substituting Li into MgO lattices.