Room temperature synthesis of diphenylmethane over novel mesoporous Lewis acid catalysts

✍ Scribed by M. Selvaraj; T.G. Lee

• Book ID: 104056909
• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 260 KB
• Volume: 243
• Category: Article
• ISSN: 1381-1169
• DOI: 10.1016/j.molcata.2005.08.020

✦ Synopsis

Highly selective synthesis of diphenylmethane (DPM) was carried out by Friedal-Crafts benzylation of benzene using benzyl chloride (BC) as alkylating agent in the presence of a flow of nitrogen under liquid phase reaction conditions over novel mesoporous SO 4 2-/Al-MCM-41 catalysts with different Si/Al ratios. For these reactions, the influences of various reaction parameters, such as different catalysts, reaction temperature, time, mmol ratios of reactants and recyclability are discussed. With increasing the Si/Al ratios of SO 4 2-/Al-MCM-41 catalysts from 21 to 83, the conversion of BC and selectivity of DPM decreased because the number of Lewis acid sites in SO 4 2-/Al-MCM-41 catalysts are found to decrease almost linearly with increasing ratios of Si/Al. Further the catalytic results were compared with those obtained by using 0.8N sulfuric acid, different Si/Al ratios of Al-MCM-41, HY, H␤, HM and H-ZSM-5 zeolites. From the comparison of the results, SO 4 2-/Al-MCM-41( 21) is found to be a highly active and recyclable heterogeneous catalyst for the highly selective synthesis of DPM. Thus, the selectivity of DPM in SO 4

2-/Al-MCM-41( 21) is higher than that in other SO 4