Selective oxidation of styrene to 1,2-epoxyethylbenzene by hydrogen peroxide over heterogeneous phosphomolybdic acid supported on ionic liquid modified MCM-41

Styrene was selectively oxidized to 1,2-epoxyethylbenzene catalyzed by phosphomolybdic acid supported on ionic liquid modified MCM-41 using hydrogen peroxide as oxidant. The synthesized catalyst was characterized by XRD, FT-IR, and N-2 adsorption-desorption analyses, and the results indicate that the sample retained mesoporous structure after ionic liquid-modified and immobilization of phosphomolybdic acid. Maximum activity was observed at a loading of 30 wt.% phosphomolybdic acid on ionic liquid modified MCM-41. Reaction conditions such as reaction time, temperature, amount of catalyst, and H2O2/styrene molar ratio were systematically optimized to obtain a maximum styrene conversion of 95.4%. 1,2-Epoxyethylbenzene selectivity of 90.2% when the reaction conditions were set to 3 h reaction time, 50 degrees C, 100 mg catalyst, and a H2O2/styrene molar ratio of 1.2. The heterogeneous catalyst is easily separated by centrifugation and was reused without deactivation after six runs. (C) 2014 Elsevier B.V. All rights reserved.