Enhancing the activity of a supported rhenium catalyst for cross-metathesis of ethene and 2-butene via promotion of boron

Abstract

The cross-metathesis of ethene and 2-butene to produce propene over a supported rhenium (Re)-based catalyst usually suffers from sluggish reaction rates, especially at low mass loading of Re. Herein, we attempt to tackle this problem with the promotion of boron through electronic modulation and selective adsorption of olefins. The boron-modified Re–2B/Al₂O₃ catalyst exhibits superior intrinsic activity, with over 19-fold propene yield with respect to the un-promoted Re–Al₂O₃ catalyst. The combined experimental analysis reveals the promotion of the boron root in the electronic withdrawal from Re oxides and selective adsorption of olefins, which together facilitate the formation of active Re–carbene species.