Reaction path of the oxidative coupling of methane over a lithium-doped magnesium oxide catalyst : Factors affecting the Rate of Total Oxidation of Ethane and Ethylene

Experiments using gas mixtures of O 2, C 2H 6 or C 2H 4 and CH 4 or He have been carried out with a Li/MgO catalyst using a well-mixed reaction system which show that the total oxidation products, CO and CO 2, are formed predominantly from ethylene, formed in the oxidative coupling of methane. It is therefore concluded that the network of reactions taking place during oxidative coupling of methane over a Li-doped MgO catalyst can be simplified to a serial reaction scheme: CH 4→C 2H 6→C 2H 4→CO x . Additional experiments have shown that the rates of gas-phase oxidation reaction of C 2H 6 and C 2H 4 are lowered by the presence of excess CH 4 or by alkali metal carbonates.