Multilayer structured MFI-type titanosilicate: Synthesis and catalytic properties in selective epoxidation of bulky molecules

A lamellar titanosilicate (LTS-1) was hydrothermally synthesized by employing a bifunctional surfactant as the structure-directing agent (SDA). Highly crystalline LTS-1 was obtained at an optimal SDA/Si molar ratio of 0.04. As-synthesized LTS-1 possessed a multilayer structure, which was constructed from a collection of 2-nm zeolite nanosheets and interlayer SDA molecules. Removing the intercalated organic species induced irregular layer stacking to a certain extent, leading to intracrystal mesopores of ca. 3.2 nm in diameter. The catalytic performance of LTS-1 was investigated in the epoxidation of various bulky alkenes with tert-butyl hydroperoxide, cumene hydroperoxide, or aqueous H2O2. LTS-1 was more active than conventional titanosilicates for reactions involving bulky alkenes and oxidants, and it was immune to Ti leaching and irreversible deactivation.

Mutilayered titanosilicate consisting of MFI-type nanosheets was hydrothermally synthesized with an aid of a bifunctional structure-directing agent. It proved to be highly active, selective, and reusable for the liquid-phase epoxidation of bulky alkenes using organic hydroperoxides as the oxidants.Figure optionsDownload high-quality image (166 K)Download as PowerPoint slideHighlights
► MFI-type mutilayered titanosilicate (LTS-1) was synthesized.
► LTS-1 is a hydrid material containing 0.5 nm micropores and 3.2 nm mesopores.
► LTS-1 is characteristic of titanosilicates and Ti-containing mesoporous silica.
► LTS-1 is robust and reusable in selective epoxidation of cyclic alkenes.
► LTS-1 is more active than TS-1 and Ti-MCM-41 in the epoxidation of propylene.