Synthesis of dipropyl carbonate by transesterification over KNO3/MCM-48

The catalytic behavior of the mesoporous sieve supported potassium nitrate KNO3/MCM-48 for the synthesis of dipropyl carbonates (DPC) by transesterification of dimethyl carbonate (DMC) with propanol was investigated. The catalysts were characterized by the techniques of X-ray diffraction (XRD), CO2 temperature-programmed desorption (CO2-TPD), FT-IR spectroscopy, N2 adsorption and X-ray fluorescence (XRF). The XRD results indicated that the structure of MCM-48 was gradually deformed with the increase in the KNO3 loading, whereas the framework of MCM-48 was basically retained until the loading of KNO3 was over 18%. IR spectra showed that KNO3 was gradually decomposed with increasing calcination temperature. The CO2-TPD showed two new types of basic site were generated, which have higher catalytic ability for the synthesis of DPC. Effects of the loading amount of active components, the calcinatory temperature, the catalyst dosage and the reaction conditions on the catalytic activity were investigated in detail and the optimized reaction conditions were acquired.

KNO3/MCM-48 exhibited very high catalytic activity under the optimized reaction conditions. Its characterization revealed that the highest catalytic activity of KNO3/MCM-48 was probably due to the completely decomposition of KNO3 and the formation of active sites at high calcination temperature. The effects of reaction conditions on the performance of the catalyst and the mechanism of transesterification were discussed.Figure optionsDownload as PowerPoint slide