Creation of Hierarchical Titanosilicate TS-1 Zeolites

Hierarchical TS-1 zeolites that possess at least two levels of porosities have aroused growing interest in the past years. The enhanced mass transfer efficiency and increased accessibility of Ti active sites in the hierarchical TS-1 zeolites greatly improve the catalytic performance by overcoming the steric and diffusional problems. In this review, recent important progress in the construction of hierarchical TS-1 zeolites is presented, including mesoporogen, mesoporogen-free, and demetallization strategies. Effective characterization methods for the Ti species and the hierarchical zeolite structures are described. The impacts of hierarchical structures on the creation of active Ti species and improvement of catalytic performances in the oxidative desulfurization and epoxidation reactions are highlighted. Finally, current challenges and future development perspectives for preparing hierarchical TS-1 zeolite catalysts are addressed.