Alkylation of naphthalene with isopropanol over tungstophosphoric acid supported on silica gel

Alkylation of naphthalene with isopropanol in the 100 mL batch stainless-steel autoclave with stirring was studied using tungstophosphoric acid (PW) supported on silica gel as catalyst. It is found that PW could be highly dispersed on the surface of silica gel until the concentration of PW reached as high as 30% by weight. It is proposed that 30%PW/SiO2 by weightexhibits higher catalytic activity because of its strong acidity and large acid amount. It is also found that the suitable reaction temperature and molar ratio of naphthalene to isopropanol are 200℃ and 1:3, respectively. Low concentration of reactants can increase the selectivity for β,β'-DIPN. The curve of distribution of products as a function of contact time indicates the feature of a consecutive reaction for the reaction of naphthalene isopropylation over this catalyst.