Effect of modifiers on the activity of a Cr2O3/Al2O3catalyst in the dehydrogenation of ethylbenzene with CO2

Abstract

Chromium oxide supported on alumina was modified with various transition metal oxides by an incipient wetness method. The effect of modifiers on the activity of 20% Cr₂O₃/Al₂O₃ catalyst in the dehydrogenation of EB with CO₂ was investigated. The activity is enhanced for ceria and vanadia modified supported chromium oxide catalysts, whereas the activity is decreased for catalysts modified with cobalt, manganese, molybdenum and zinc oxides. Carbon monoxide was detected in the course of the reaction, suggesting that carbon dioxide, which is one of the most important greenhouse gases, could be utilized as a mild oxidant in the oxidative dehydrogenation of ethylbenzene to styrene over unmodified and modified Cr₂O₃/Al₂O₃ catalysts.