The role of urea in regulating the structural properties of Zr–Sn-based oxide catalysts for direct synthesis of dimethyl carbonate from CO2 and methanol

The aim of this work was to explore the influences of urea as a precipitant on the structural and catalytic performances of Zr–Sn–O catalysts for direct synthesis of DMC from CO2 and CH3OH. Zr–Sn–O catalysts were characterized by XRD, TEM, Raman spectroscopy, XPS, NH3-TPD, CO2-TPD, and N2 adsorption. The results confirmed that urea used as a precipitant had a significant impact on the particle size, amount of oxygen vacancies, acid–base properties, BET surface area, pore structures and catalytic performances of the studied catalysts. The Zr–Sn–O-57.5 catalyst exhibited high catalytic activity with a DMC yield of 1.74 mmol gcat−1 and methanol conversion of 0.28%. Furthermore, the catalytic performance of Zr–Sn–O catalysts is directly related to the BET surface area. Thus, this work provides a new strategy for preparing catalysts for the direct synthesis of DMC.