Low-temperature catalytic alkylation of benzene by propane

Interaction of benzene with propane (C6H6:C3H8 = 1:9) was studied at 453-623 K in the presence of acidic HY-zeolite Pt, Re/Al2O3 bimetal alumina catalysts (APRC), and mixed (50% APRC + 50%HY) catalyst (mixed catalyst, MC) systems with Pt and Re content 0.3 and 0.5%, respectively. Unlike inactive separate components, MC activates benzene dehydroalkylation (DHA) by propane even at 453 K to form isopropylbenzene (IPB) and hydrogen. Increased temperatures lead to the formation of additional products, such as propene (at 523 K) and other alkylbenzenes (at 573 K). Activation of benzene-propane mixture is characterized by an induction period prior to the formation of conversion products. MC treatment by ammonia at 423 K leads to increase of selectivity of IPB formation. The mechanism of low-temperature DHA of benzene over MC has been proposed. (C) 2003 Published by Elsevier Science B.V.