Polymer-immobilized aluminium or copper tungstophosphates and tungstosilicates as new catalysts in anisole acylation

Abstract

New materials with spherical shape were obtained from aluminium or copper salts of tungstophosphoric and tungstosilicic acids immobilized in a polymeric blend prepared with polyvinyl alcohol and polyethylene glycol by the freeze-thawing method. It is observed that the salts retain the Keggin structure of the heteropolyanions during their synthesis and immobilization. There is an almost constant distribution of the salts along the sphere width when they are included in the PVA-PEG blend. Also, the immobilized salts present very strong acid sites. The catalytic activity in the anisole acylation of the immobilized aluminium salts was higher than that of the catalysts obtained from the copper salts.