A Novel Brønsted-Lewis acidic catalyst based on heteropoly phosphotungstates: Synthesis and catalysis in benzylation of p-xylene with benzyl alcohol

Abstract

A novel Brønsted-Lewis acidic catalyst, Hf0.5[TEAPS]PW12O40, has been prepared by the replacement of protons in neat phosphotungstic acid with both organic and metal cations and characterized by FT-IR, Py-IR, XRD, TG-DTG, ICP-AES, BET, elemental analysis and n-butylamine potentiometeric titration techniques. This hybrid heterogeneous catalyst with both Brønsted and Lewis acidity can efficiently promote the conversion of dibenzyl ether, the self-condensation product of benzyl alcohol, to the benzylation products, as well restrain the polybenzylation of aromatics. As a result, it exhibits excellent catalytic activity and selectivity in the benzylation of p-xylene with clean benzylation reagent benzyl alcohol. Thus, an environmentally friendly route for the benzylation reaction of p-xylene with high atomic economy has been developed by this reusable Hf0.5[TEAPS]PW12O40 catalyst.