Synthesis of dimethylcarbonate from urea and methanol catalyzed by various metal oxides and salts

Abstract

Various metal oxides and metallic salts were used as a catalyst in the synthesis of dimethyl carbonate (DMC) from urea and methanol in an autoclave. The results indicated that the hydrated metallic salt is most catalytically active in DMC synthesis among various metal oxides and salts considered in this work. Furthermore, a binary catalyst, viz, Zn(NO3)2 combined with hydroxyl containing compounds, can noticeably enhance the yield of DMC, in comparison with the single catalyst of both Zn(NO3)2 and the hydroxyl containing compound, which may be ascribed to a synergistic effect between Zn(NO3)2 and the hydroxyl group. Among various binary catalysts, Zn(NO3)2-SiO2 exhibits the best catalytic performance; the yield of DMC reaches 4.5% over Zn(NO3)2-SiO2 with a Zn(NO3)2 to SiO2 weight ratio of 2.