MICROKINETIC ANALYSIS OF METHANE DIMERIZATION REACTION

Microkinetic analysis of experimental kinetic data on methane dimerization at low conversions over alkali-metal-promoted alkaline earth oxide catalysts reinforces mechanistic ideas proposed previously in the literature and suggests new conclusions. Active sites for this reaction appear to be produced via two elementary steps. In the first step, surface peroxide species are formed by adsorption of gaseous dioxygen, and in the second step methane-activating sites are produced via O-O bond cleavage. Gas-phase C2 combustion alone cannot account for the observed C2 yield limit, and surface-catalyzed C2 combustion is suggested to play an important role in determining selectivity.