Alkylation of benzene with ethanol and ethylene over H-ZSM-5 zeolite has been studied theoretically by the ONIOM2 (B3LYP/ 6-31G(d):UFF) method. A 40T cluster model was selected to simulate the acidic sites located at the intersection of channels in ZSM-5 zeolite. The difference of the reaction mechanisms using the two kinds of alkylation reagents has been analyzed and compared according to the formation energy and reaction activation energy (Ea). The results showed that alkylation of benzene with ethanol occurred via stepwise mechanism. The Ea for the formation of ethoxide intermediate was 170.34 kJ/mol. Alkylation of benzene with ethylene occurred through both concerted mechanism and stepwise mechanism, and they were competitive to each other. These two paths were only slightly different in the activation energy. Ea for the concerted mechanism was 167.24 kJ/mol, while it was 155.20 kJ/mol for the formation of ethoxide intermediate in the stepwise mechanism.
|Original language||English (US)|
|Number of pages||6|
|Journal||Cuihua Xuebao / Chinese Journal of Catalysis|
|State||Published - May 1 2009|
All Science Journal Classification (ASJC) codes