Polyoxometalate-Supported Ionic Liquid@Core-Shell Polymer Nanoparticles: Novel Pickering Interfacial Catalysts for Efficient and Safe Epoxidation of Allyl Chloride with Low-Concentration H2O2

O/WPIC system built by POM-supported ionic liquid@core-shellpolymer nanosphere realized efficient epoxidation of allyl chloridewith low-concentration H2O2. Epoxidation of allyl chloride with H2O2 isan environment-friendly process for the synthesis of epichlorohydrin.However, due to the mass transfer barrier at the liquid-liquidinterface, the reactivity is greatly inhibited. Although the reactionrate can be improved by increasing the H2O2 concentrationor temperature, this makes the reaction more uncontrollable and dangerous.Herein, we reported a safe and green process in which a novel nanoparticlecomposite is used to catalyze the epoxidation of allyl chloride withlow-concentration (9.6 wt %) H2O2 under solvent-freeconditions. The composite is based on polyoxometalate-supported ionicliquid grafted onto core-shell nanospheres, which built anefficient Pickering emulsion catalysis system. Systematic experimentsshow that the catalytic activity and emulsion properties are stronglyinfluenced by catalyst surface properties, catalyst dosage, and oil/watervolume ratio. Benefiting from the high stability of the core-shellstructure, the catalyst maintained high catalytic efficiency and emulsionstability after eight consecutive runs.