Hierarchical Ti-containing hollownest-structured zeolite synthesized by seed-assisted method for catalytic epoxidation of alkenes efficiently

Recently, a Ti-containing hollownest-structured zeolite (Ti-HSZ) material with the shell constructed by randomly intergrown MWW (framework type code) flaky crystals has been synthesized through one-step rotating hydrothermal method within 3.5 days, which shows predominant catalytic property for the epoxidation of alkenes . Herein, it is firstly reported that the crystallization efficiency of Ti-HSZ material can be notably increased by applying seeds-assisted synthesis method. Thus-crystallized materials have been characterized by XRD , UV–vis, XPS , SEM , TEM, FT-IR, and N 2 adsorption-desorption. Moreover, the key controlling factors are revealed to include the addition percentage of seed crystals, rotating rate and filling degree of autoclave. When 2 wt% or 3 wt% seed crystals are added into the reaction gel, the crystallization time of Ti-HSZ can be sharply reduced to 2.5 days or even 2.0 days, respectively. Particularly, thus-synthesized Ti-HSZ-SM material still maintains hollownest morphology characteristic and excellent catalytic activity and catalytic stability. About 95% allyl chloride can be converted into corresponding epoxide when using H 2 O 2 as oxidant, and about 85% cyclopentene and 87% cyclooctene can be converted into corresponding epoxides when using TBHP as oxidant, with the selectivity for epoxides of nearly 100%.