Insight into the Effect of Lewis Acid of W/Al-MCM-41 Catalyst on Metathesis of 1-Butene and Ethylene

Elucidating the role of support nature of the W catalyst is of great importance for the metathesis reaction of 1-butene and ethene to propene. Herein, a series of highly dispersed W/Al-MCM-41 catalysts were prepared by impregnating W on the Al-MCM-41 supports with different Si/Al ratios. Multi-characterizations together with DFT calculations revealed that the Lewis Acid formed by framework Al could strength the interaction between W metal and Al-MCM-41 support and promote the formation of the W-(O-Si) n species, which are the main active sites in the metathesis reaction. Through the optimization of various parameters (such as Si/Al ratio, W metal loading, pretreatment atmosphere and reaction temperature), optimal 1-butene conversion (94%) and propene selectivity (81%) are obtained on the N-2-pretreated 10W/70-MCM-41 catalyst at 350 degrees C under atmospheric pressure. This work may provide some new insights for the rational design of W based catalysts in the olefin metathesis system.