Dehydrogenation of ethylbenzene with an activated carbon-supported vanadium catalyst

Dehydrogenation of ethylbenzene over supported vanadium catalysts was carried out at 723-923 K, W/F of 35-105 g-cat h/mol in a carbon dioxide atmosphere (carbon dioxide/ethylbenzene of 50-70 mmol/mmol) and in an argon atmosphere. The catalyst, 1.0 mmol of vanadium loaded on 1 g of activated carbon, afforded the highest ethylbenzene conversion of 67.1%, a styrene yield of 54.2% and a styrene selectivity of 80.8% at 550 K with a W/F of 70 g-cat h/mol of ethylbenzene in carbon dioxide. Ethylbenzene conversion and styrene yield in the presence of carbon dioxide were 14.0% higher than those in argon. During the course of the reaction, carbon dioxide was reduced to the corresponding amount of carbon monoxide against the styrene yield. As a result, the same amount of water was produced. (C) 2000 Elsevier Science B.V. All rights reserved.