Preparation of Solid Superacid SO۴۲-/ZnO-TiO۲ and Its Action on Synthesis of Dimethyl Carbonate from Urea and Methanol

SO۴۲-/ZnO-TiO۲ catalyst was prepared by sulfating ZnO-TiO۲ powders with H۲SO۴ solution. The catalyst was characterized by XRD, IR and Hammett indicator. The catalyst showed strong acidity(H۰ ≦-۱۶.۰). The optimum conditions are found that the calcination temperature is ۸۲۳K and the soaked consistency of H۲SO۴ is ۱ mol/dm۳. Then SO۴۲-/ZnO-TiO۲ was applied as the catalyst in the catalytic synthesis of dimethyl carbonate(DMC) from urea and methanol under the optimum conditions and revealed higher catalytic activity. On condition that the reaction time is ۶h, the reaction temperature is ۴۳۳K, the mass percent of the catalyst used in the reactants is ۵wt.%, and the molar ratio of methanol to urea is ۱۴, the yields of DMC can reach ۲۷.۹%.

کلیدواژه ها:

Preparation ، Solid superacid ، Synthesis ، Dimethyl carbonate ، Catalytic activity