Cesium salts of heteropoly acid immobilized mesoporous silica: an efficient catalyst for acylation of anisole.

A series of Cs salt of phosphotungstic acid (Cs-PTA) supported on MCM-41 (Cs-PTA/MCM-41) was synthesized by a wet impregnation method and thoroughly characterized by using various analytical techniques, viz. X-ray diffraction, UV-Vis diffused reflectance spectroscopy (UV-Vis DRS), nitrogen adsorption desorption, scanning electron microscopy (SEM), Infrared spectra (FTIR), temperature programmed reduction (TPR), and temperature programmed desorption (TPD). The spectroscopic results revealed that Cs-PTA is highly dispersed on a MCM-41 surface. The 50 wt.% Cs-PTA supported on MCM-41 showed remarkable catalytic performance toward acylation of anisole reaction. The catalyst is regenerable by simple calcinations without appreciable loss in catalytic activity.