Controlled detitanation of ETS-10 materials through the post-synthetic treatment and their applications to the liquid-phase epoxidation of alkenes

Abstract

Treatments of ETS-10 titanosilicates with HCl, NH 4Cl or citric acid led to the change in the coordination environment of Ti. These treatments also led to the partial extraction of Ti from the framework of ETS-10. The local structural changes brought about the formation of the active sites for the epoxidation of cyclohexene with H 2O 2. The highest epoxidation activity and efficiency of H 2O 2 as an oxidant were achieved when the original [Na, K]-type ETS-10 was treated with 3.7 mol dm −3 NH 4Cl solution followed by the calcination at 723 K.