The role of urea in regulating the structural properties of Zr-Sn-based oxide catalysts for direct synthesis of dimethyl carbonate from CO 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 CO 2 and CH 3 OH. Zr-Sn-O catalysts were characterized by XRD, TEM, Raman spectroscopy, XPS, NH 3 -TPD, CO 2 -TPD, and N 2 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 g cat −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. Zr-Sn-O catalysts were prepared with urea as precipitant. It was found that the usage of urea had a crucial effect on the structure properties and the catalytic activity of direct synthesis of DMC from CO 2 and methanol.