Synthesis of ethylene carbonate by alcoholysis of urea over Zn-Zr mixed oxides

Zn/Zr mixed oxide catalysts with different Zn-Zr molar ratios were prepared by coprecipitation method, and their catalytic performance for synthesis of ethylene carbonate (EC) from ethylene glycol and urea were investigated. The catalysts were also characterized by XRD, FT-IR, XPS, Raman, SEM, HRTEM and CO 2 -TPD. Compared with ZnO, Zn/Zr mixed oxide has suitable basicity and low lattice oxygen binding energy. The catalyst with Zn/Zr ratio of 5:1 showed the highest catalytic activity in the reaction with the EC yield of 91%. The results revealed that the yield of EC was closely related to the amount of the basic sites on the catalyst surface. Based on the characterization results, a possible mechanism was proposed.