Theoretical comparative study on the mechanism of gas phase epoxidation of propylene about complete and defective dimer MoOx

Abstract

Density Functional Theory is used to calculate the epoxidation of propylene on the dimer MoOx by Gaussian 09 software. We calculate the dehydrogenation process of propylene and the formation process of propylene oxide. It is found that the activity of O in Mo-O-Si, which is beneficial to the dehydrogenation process of propylene, is high. Furthermore, we establish a dimer MoOx model with defect sites, and find that the defect sites in the dimer MoOx can activate O2 (O22-) effectively. Consequently, the catalyst containing defect sites is conducive to the selectivity of propylene oxide.