Toluene Alkylation with Methanol to p-Xylene over Heteropoly Acids Supported by Clay

The alkylation of toluene with methanol for the selective formation of p-xylene was systematically studied. Very few studies have been reported on the use of superacids such as heteropolyacids on cheap supports, such as clay. This article deals with the use of different heteropoly acids (HPAs), viz, Dodeca-Tungstophosphoric acid [H3PO4·12WO3·xH2O] (TPA), Dodeca-Molybdo phosphoric acid ammonium salt hydrate [H12Mo12N3O40P+aq] (DMAA), Dodeca-Molybdo Phosphoric acid (PMA) on clay (Montmorillonite, K-10) and as such plain clay. This comparative study reveals that 20%PMA/Clay shows 62% toluene conversion and 100% selectivity toward p-xylene.