Alkylation of benzene with ethanol to ethylbenzene using synthesized HZSM-5 catalysts: effects of hydrothermal synthesis and operating conditions

Abstract

Ethylbenzene (EB) is a key intermediate in the production of styrene. HZSM-5 zeolites seem to be active for the alkylation of benzene with ethylene because of its special structure and acidity. However, the direct use of ethanol as an alkylating agent with benzene for this reaction has gained more attention due to green chemistry aspects as well as a long stable catalyst life. It was reported that the morphology of HZSM-5 catalysts affected the selectivity to EB for benzene alkylation with ethanol. Since a HZSM-5 catalyst with a SiO2/Al2O3 ratio of 195 gave a high selectivity to EB as compared to the selected commercial HZSM-5 catalysts, the effects of parameters used in the synthesis of HZSM-5 catalysts on the alkylation of benzene with ethanol were investigated in this work. It was observed that the catalyst hydrothermally synthesized at 150℃ for 48 h provided a relatively suitable crystallinity, surface characteristic, and Bronsted acid sites, resulting in a higher catalytic activity in terms of ethanol conversion and selectivity to EB.