Direct oxidation of methyl radicals in OCM process deduced from correlation of product selectivities

Selectivity of hydrogen in reaction of oxidative coupling of methane (OCM) was evaluated over the MxOy-BaCO3 (MxOy: La2O3, Sm2O3, MgO, CaO) catalysts. Correlation of product selectivities was thus discussed. From the correlation of product selectivities, it is revealed that the carbon oxides (CO and CO2) were most probably formed from the direct oxidation of methyl radicals under the conditions adopted in the present work. This is also in accordance with the OCM mechanism proposed in literature.