Immobilization of 12-tungstophosphoric acid on LaSBA-15 and its catalytic activity for alkylation of o-xylene with styrene

12-Tungstophosphoric heteropoly acid (HPW) catalysts supported on La-incorporated mesoporous molecular sieves (LaSBA-15) with various acid loadings were prepared by impregnation, and their physicochemical properties were characterized by elemental analysis. X-ray diffraction, nitrogen adsorption, FT-IR spectroscopy, diffuse reflectance UV-vis spectra and NH3 temperature-programmed desorption. It was found that LaSBA-15 could accommodate discrete HPW due to its large pore volume and high surface area, and meanwhile the Keggin structure of heteopolyaniona could be retained. Moreover, these catalysts were investigated in the alkylation of o-xylene with styrene. Results showed that 30%HPW/LaSBA-15 catalyst had the highest strength of acidic sites and the best catalytic activity under optimum conditions. Compared with 30% HPW/SBA-15 catalyst, the 30%HPW/LaSBA-15 one had better regeneration, which was due to the strong interaction between the HPW and the support in the presence of La, thus prevent HPW leaching from the support. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.