nV-MCM-41催化剂的制备及其催化CO2氧化丙烷脱氢反应性能
摘要
Abstract The nV-MCM-41 catalysts were prepared by one-step hydrothermal synthesis and applied to the oxidative dehydrogenation of propane (ODHP) in the presence of CO2. Several state-of-the-art characterization methods were performed to explore the correlation between catalytic performance and the physicochemical characterizations of the catalysts. Because moderate amounts of V species were introduced into the framework of MCM-41, the catalyst maintained a large specific surface area, a highly ordered mesoporous structure, and highly dispersed V active sites (monomeric and dimeric V oxide species), while the high-vanadium-doping catalysts caused an enhancement in the number of acidic sites and V2O5 crystallites. The ODHP reaction showed that the 6.8V-MCM-41 (V content 6.8 wt%) catalyst exhibits high activity and stability, and the C3H8/CO2 molar ratio (1:4) was suitable. The promoting effect of CO2 on the oxidative dehydrogenation of ODHP was demonstrated as the reaction coupling mechanism and “lattice oxygen” mechanism.