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 O₂, C₂H₆ or C₂H₄ and CH₄ 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 CO₂, 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: CH₄→C₂H₆→C₂H₄→CO_x. Additional experiments have shown that the rates of gas-phase oxidation reaction of C₂H₆ and C₂H₄ are lowered by the presence of excess CH₄ or by alkali metal carbonates.