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A number of Fe-containing solid catalysts, such as Fe-modified ZSM-5 type zeolites (Fe2O3/H-ZSM-5, SO42−/Fe2O3/H-ZSM-5, H-FeMFI and H-FeAlMFI), Fe-modified H-β zeolites (Fe2O3/H-β and SO42−/Fe2O3/H-β), Fe2O3 supported on meso-porous Si-MCM-41, silica gel or macro-porous silica–alumina commercial catalyst carrier (SA-5205), and FeCl3 impregnated on 13X zeolite, Si-MCM-41, silica gel or commercial clays––montmorillonite K10 (Mont K10) or kaolin, have been compared for their performance in the benzylation of benzene by benzyl chloride (80 °C). Among these catalysts, the Fe2O3/H-β (or H-ZSM-5) and FeCl3/Mont K10 (or Si-MCM-41) are found to be highly promising ones for the benzylation, even in the presence of moisture. These catalysts can also be reused in the reaction but with reduced activity. No direct relationship is observed between the acidity (measured in terms of ammonia chemisorbed at 50 or 200 °C) and the benzylation activity of the catalysts. The benzylation activity is controlled mainly by the redox properties of the catalyst. The selectivity for diphenyl methane in the benzylation was found to vary from catalyst to catalyst. [Copyright &y& Elsevier]

Liquid phase benzoylation of benzene by benzoyl chloride over In2O3, Ga2O3 and ZnO supported on high silica mesoporous MCM-41 at 80 °C has been investigated. The supported In2O3, Ga2O3 and ZnO catalysts showed high activity for the benzoylation of benzene. The redox function and activation of aromatic substrate by the supported basic In2O3 and amphoteric Ga2O3 or ZnO seem to play a very important role in the benzoylation process. Among the catalysts, the In2O3/Si-MCM-41 showed the highest activity for the benzoylation of benzene. The activity of this catalyst for the benzoylation of benzene and substituted benzenes is in the following order: anisole>mesitylene>p-xylene>toluene>benzene. The In2O3 (or Ga2O3)/Si-MCM-41 showed high benzoylation activity of benzene even in the presence of appreciable amounts of moisture in the reaction mixture. Solvent and its nature (polar or non-polar) also play important role in the benzoylation over the supported In2O3 catalyst. [Copyright &y& Elsevier]

Liquid phase benzylation of benzene by benzyl chloride to diphenyl methane over InCl3, GaCl3, FeCl3 and ZnCl2 supported on commercial clays (viz. Montmorillonite-K10, Montmorillonite-KSF and Kaolin) or on high silica mesoporous MCM-41 (at 60, 70 and 80 °C) has been investigated. The supported InCl3, GaCl3 and FeCl3 showed high activity for the benzylation of benzene. The redox function created due to the impregnation of the clays or Si-MCM-41 by InCl3, GaCl3, FeCl3 or ZnCl2 seems to play a very important role in the benzylation process. Among the catalysts, the InCl3/Mont.-K10 showed both high activity and high selectivity for the benzylation. The activity of this catalyst for the benzylation of different aromatic compounds is in the following order: benzene>toluene>mesitylene>anisole. The InCl3 (or GaCl3)/Mont.-K10 (or Si-MCM-41) catalyst showed high benzene benzylation activity even in the presence of moisture in the reaction mixture. The catalyst can also be reused in the benzylation for several times. Kinetics of the benzene benzylation (using excess of benzene) over the supported metal chloride catalysts have also been thoroughly investigated. A plausible reaction mechanism for the benzylation over the supported metal chloride catalysts is proposed. [Copyright &y& Elsevier]