Thermodynamic and kinetic study on the catalytic epoxidation of allyl chloride with H2O2 by new catalyst [(C18H37)2(CH3)2N]3{PO4[W(O)(O2)2]4}

Abstract

The preparation of epoxy compounds by catalytic oxidation with hydrogen peroxide, an environmentally friendly oxidant, is beneficial to reducing pollutants. A new temperature-controlled phase transfer catalyst, [(C18H37)2(CH3)2N]3{PO4[W(O)(O2)2]4}, was developed for the catalytic epoxidation of allyl chloride with H2O2. Allyl chloride could be epoxidized to epichlorohydrin (ECH) in 97.1% conversion and more than 99% selectivity with equimolar H2O2 and as-prepared catalyst. The catalyst could be precipitated from the solution after reaction by cooling to 10 °C and it was easily recycled five times without significant loss of activity. The catalytic mechanism was proved by FT-IR and 31P NMR spectrum. The constant interface cell device was employed for the kinetic study, and the results indicated that the interface reaction was the control step of the reaction process. The prepared catalyst exhibited obvious interfacial activity and aggregated at the interface.