SURFACE PROCESSES IN THE CATALYTIC OXIDATIVE COUPLING OF METHANE TO ETHANE

Recent results on surface reaction steps in the oxidative coupling of methane (OCM) obtained from (1) transient experiments and (2) a microk inetic analysis are summarized. The interaction of methane and oxygen with MgO and Sm2O3 surfaces was investigated by applying H/D- and oxyg en-isotope-exchange reactions. The role of short-lived adsorbed oxygen species in methane activation and product formation over MgO and Sm2O 3 catalysts is discussed. Furthermore, elementary reaction steps and t heir rate constants are derived for the oxidative conversion of methan e to COx and ethane from kinetic data for different (CaO)(x)(CeO2)(1-x ) catalysts; the rate constants are related to the solid's properties, i.e., electron and O2- conductivity.