| Titanium silicalite has been shown to be an efficient catalyst for the epoxidation of olefins with hydrogen peroxide. The epoxidation of propene has been investigated to some extent and proved to be a clean and economically viable alternative to the existing processes of propene epoxide production.In this work, TS-1 was synthesized by using inorganic sources of Ti and Si, tetrapropylammonium bromide (TPABr) as template and ammonia as base in the presence of seeds. The influences of seeds'crystallization time on TS-1 were studied by adding seeds with different crystallization time. The characterization of the synthesized TS-1 was carried out by use of IR, XRD, UV-Vis and SEM. The results showed that all samples synthesized with inorganic sources of Ti and Si possessed typical TS-1 characteristics; the crystals synthesized by adding TS-1 as seeds were in the form of rectangular plank (0.4-2.2μm); the addition of seeds (TS-1, S-1 or mother liquor) decreased the crystal sizes, promoted the nucleation and enhanced the crystallization rate of the zeolites; longer crystallization time of seeds resulted in higher rate of crystallization and higher crystallinity of the final products, but after 72h crystallization, the crystallinity became constant.TS-1 was also synthesized by using organic sources of Ti and Si, with TPAOH obtained by ion exchange as the template. The addition modes and the hydrogenolysis time of Si source as well as the amount of isopropanol were investigated. The results showed that in the addtion process of template into Si and Ti source, pH value and the viscosity of the gels did not change appreciably, but the time of gel formation was shortened; controlling the time of Si source hydrolysis within 10-30 min facilitated the entry of Ti into the zeolite framework; the decrease of the amount of isopropanol may lead to the improvement of the catalytic performance of TS-1; with all organic materials, the synthesized TS-1 had the particle sizes of 180-330nm.
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