Reaction-controlled Phase-transfer Catalysis for Epoxidation of Styrene

In the present work,epoxidation of styrene with hydrogen peroxide catalyzed by reaction-controlled phase-transfer catalyst of quaternary ammonium heteropolyphosphatotungstate is described. The factors such as solvents,the amount of H2 O2,the amount of catalyst,reaction temperature,reaction time,and the concentration of styrene were investigated. It was found that the optimized conditions are ethyl acetate as the solvent,n( styrene) ∶ n( H2O2) ∶ n( catalyst) = 300∶300∶1,the mass fraction of styrene is 10% ,60 ℃,6 h. Under the optimized conditions,the conversion of styrene is 85. 5% ,and the selectivity of styrene oxide is 84. 9%. The catalyst can be reused with good stability.