THE KINETIC AND MECHANISTIC ASPECTS OF THE OXIDATIVE DEHYDROGENATION OF ETHANE OVER LI/NA/MGO CATALYSTS

Kinetic and mechanistic aspects of the oxidative dehydrogenation of ethane catalysed by Li/MgO and Li/Na/MgO have been investigated. Initial rate measurements at 600-degrees-C revealed that the Li/MgO catalyst produced C2H4, CO2, CO and H-2 by parallel reactions whereas the sodium-promoted catalyst produced only C2H2 and CO2, again by parallel reactions. Experiments were also carried out in which water and carbon dioxide were added to the feed, these being designed to study the mechanism of hydrogen production. The results indicate that the hydrogen and carbon monoxide are unlikely to have been produced by steam reforming or carbon dioxide reforming of ethane or by the water-gas shift reaction; they are possibly formed directly from the ethane via surface ethoxy species.