Toluene alkylation with 1-octene over supported heteropoly acids on MCM-41 catalysts

The liquid phase alkylation of toluene with 1-octene catalyzed by bulk and MCM-41 supported Keggin-type heteropoly acids (HPA), such as tungstophosphoric acid (HPW), tungstosilicic acid (HSiW), and molybdophosphoric acid (HPMo), has been studied. Among these catalysts, the supported catalysts exhibited more activity than bulk HPA, especially, HSiW and HPW supported on MCM-41 (HSiW/MCM-41 and HPW/MCM-41). The conversion of 1-octene was 100% and selectivity for monoalkylation products was 99.9% after 2 h of reaction at 120, C over HSiW/MCM-41. The studies of FT-IR, thermogravimetric analyses (TGA) and X-ray diffraction (XRD) confirmed the presence and high dispersion of HPA on MCM-41 mesoporous structure. We also examined the reusability of the supported catalysts. The catalysts retained their catalytic activity for five reaction times in the present study. These results indicate that HSiW/MCM-41 and HPW/MCM-41 are excellent catalysts for this reaction under mild conditions. (C) 2008 Elsevier B.V. All rights reserved.