Polyoxometalate-Supported Ionic Liquid@Core–Shell Polymer Nanoparticles: Novel Pickering Interfacial Catalysts for Efficient and Safe Epoxidation of Allyl Chloride with Low-Concentration H<sub>2</sub>O<sub>2</sub>
Jia Liu, Yan Liu, Ying Liu, Yi Wang, Fangqin Wu, Zheng Zhou, Zhibing Zhang
Abstract
Epoxidation of allyl chloride with H 2 O 2 is an environment-friendly process for the synthesis of epichlorohydrin. However, due to the mass transfer barrier at the liquid–liquid interface, the reactivity is greatly inhibited. Although the reaction rate can be improved by increasing the H 2 O 2 concentration or temperature, this makes the reaction more uncontrollable and dangerous. Herein, we reported a safe and green process in which a novel nanoparticle composite is used to catalyze the epoxidation of allyl chloride with low-concentration (9.6 wt %) H 2 O 2 under solvent-free conditions. The composite is based on polyoxometalate-supported ionic liquid grafted onto core–shell nanospheres, which built an efficient Pickering emulsion catalysis system. Systematic experiments show that the catalytic activity and emulsion properties are strongly influenced by catalyst surface properties, catalyst dosage, and oil/water volume ratio. Benefiting from the high stability of the core–shell structure, the catalyst maintained high catalytic efficiency and emulsion stability after eight consecutive runs.