Key Mechanistic Insight into the Direct Gas-Phase Epoxidation of Propylene by the RuO2-CuO-NaCl/SiO2 Catalyst

摘要

The discovery of the RuO2-CuO-NaCl/SiO2 catalyst for the direct gas-phase epoxidation of propylene to propylene oxide created a potentially promising path towards developing a high-performing catalyst of substantial commercial value and opened a new challenge in catalysis research. In this work, studies following up this discovery are presented to reveal critical insight into the catalytic mechanism on the trimetallic catalyst. Small crystalline CuO particles, in close proximity of RuO2, were determined from temperature-programmed reduction and high-resolution transmission electron microscopy studies to be the site for propylene oxide synthesis. In addition, the presence of NaCl was confirmed to suppress the formation of CO2.