Enhancement of Propylene Metathesis Performance of MoO₃/Al₂O₃ with Promotion of Phosphoric Acid

Catalytic olefin metathesis represents a vital reaction in the chemical industry, as it provides a feasible route for the interconversion of olefins. However, traditional supported catalysts usually suffer from low activity due to sluggish kinetics for the formation of catalytically active metal-carbene species. This work tackles this issue by taking phosphoric acid as a promoter and constructing a Br & oslash;nsted acidic site to cooperate with the MoOx sites, thus facilitating the formation of Mo-carbene. It turns out that the turnover frequency of propene metathesis over the Mo-P/Al2O3 catalyst is 7.1 times higher than that over the unmodified Mo/Al2O3 catalyst. The combined characterization reveals the promotion of phosphorus results from the alignment of olefin toward adjacent MoOx and thus facilitates formation of active Mo-carbene species.