Benzene-Carbon Dioxide Reaction over Alkaline Earth Metal Oxide Catalysts

The benzene-carbon dioxide reaction was performed over alkaline earth metal oxide catalysts at temperatures in the range 973-1173K to investigate the reaction sequence in hydrocarbon gasification and the catalytic role of these oxides. To discuss the difference in the reactivities of benzene and hexane, we propose a reaction scheme as follows: the reaction proceeds via the intermediate carbon deposited by direct decomposition of benzene on the surface of the catalyst producing hydrogen simultaneously, and the rapid reverse water gas shift reaction concurrently occurs to give carbon monoxide and steam in equilibrium composition. The catalytic activity was determined on the balance between the rate of formation of intermediate carbon and the rate of its gasification. Characterization of catalysts by means of 1-butene isomerization leads to a confirmation that carbon accumulates on an inactive part of the catalyst surface.