Catalytic synthesis of dimethyl carbonate from urea and methanol using SnO2 nanoplates†
Abstract
SnO2 was synthesized using precipitation method, hydrothermal method, and sol–gel combustion method. The catalysts were characterized using various physiochemical techniques like X-ray diffraction (XRD), N2 adsorption–desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron microscopy (XPS), and CO2-temperature programmed desorption (CO2-TPD). The catalysts were mesoporous in nature, and it was seen that the catalysts synthesized from sol–gel method (SnO2 (S)) showed tetragonal morphology with high crystallinity. Moreover, SnO2 (S) possessed high basicity with medium basic strength. The catalysts were further used for the synthesis of dimethyl carbonate (DMC) using urea and methanol. The study demonstrates that SnO2 catalysts were found to be effective for the DMC synthesis through urea route. Effect of Reaction conditions were optimized, and SnO2 (S) was found to give 51.9% DMC yield at 170 °C, 7 hours of time, with 0.2 g of the catalyst. The catalyst was easily recovered and reused, and the structure of SnO2 was found to be intact after the reaction.