Oxidative methylation of toluene with methane over alkali-promoted Y2O3–CaO catalysts

The Y2O3–CaO catalyst system, which is active for the oxidative coupling of methane to form C2 hydrocarbons, catalysed the oxidative methylation of toluene using methane as the methylene source, to give ethylbenzene and styrene; the addition of alkali metal oxide greatly improved the selectivity in the order:Li2O > Na2O > K2O.