Amorphous TiO2–SiO2 composites as selective heterogeneous catalysts for the oxidation of styrene to 1, 2-epoxyethylbenzene.

A series of amorphous TiO2–SiO2 composite oxides with different TiO2 contents were prepared by a one-step co-precipitation process as catalysts for selective oxidation of styrene to 1, 2-epoxyethylbenzene with aqueous hydrogen peroxide in acetonitrile. The amorphous TiO2–SiO2 composites are found to be much more catalytically active than the one with partially crystallized TiO2. The TiO2–SiO2 composite with 40 wt% TiO2 (TSCO-3) presents the best catalytic performance. Under the optimal reaction conditions, the styrene conversion can reach 61.0% with a high selectivity of 95.4% to 1, 2-epoxyethylbenzene upon 1 h reaction. Moreover, the TSCO-3 catalyst exhibits a good cycling stability. The excellent catalytic performance can be attributed to the numerous exposed active centers and the fast release of the product from the active centers. [ABSTRACT FROM AUTHOR]