Synthesis Of Titanium Silicality By Microwave Hydrothermal Method And Its Catalytic Performance For Epoxidation Of Allylchloride

As a new type of green catalyst,Titanium silicalite-1 (TS-1) has show great active and highly selective in a series of oxidation reactions with apueous H2O2 as the oxidant. TS-1 has become a hot pot in catalytic field because of its excellent catallytic under mild conditons and the final product is water. Synthesis of TS-1 is classic hydrothermal sythesis. But there are some problems existed such as it is difficult to separate and recycle because its small catalyst, and the high cost of sythetic materials, long crystallization time which hinder its application. Our task force focous on synthesis of TS-1 by hydrothermal with inorganic materials, which is low cost, big size. But long crystallization time and energy consuming are also existed. The application of microwaves to chemical synthesis has gratually developed in recent years, because microwave irradiation can shorten the crystallization time and synthesis high crystallinity of zeolite with little time and energy-consuming.In this communication,we reported the TS-1 zeolite which was synthesized by using inorganic materials under microwave irradiation and conventional heating. SiO2, Ti(SO4)2 solution, TPAOH, NH4OH and water were used as materials. We investigated the influence between the amount of TPAOH and crystallization time and the best crystallization time unnder different amount of template. The best molar ration is 1Si:(0.013-0.035)Ti:0.14TPA+:(25-50)H2O:(20-30)NH3.H2O. The catalytic properities of TS-1 was investigated by epoxidation of allys chloride. The TS-1 samples were characterized by XRD, IR, UV-Vis, SEM to make sure the crystal structure,crystallinity, grain sizes and norphologies, the existence in the form of titainum, etc. And the results showed that TS-1 synthesised under microwave irradiational showed large grain, low non-framework titanium contend, adhesion among grais, better catalytic performance than those synthesised with the traditional hydrothemal. Meanwhile the effect of the crystallization temperature,microwave power on the synthesis of TS-1 were investigation. The optimum crystallization temperature is 170℃, and the microwave power is 1600 W.Secongdary crystallization can improve the catalyst performance of TS-1. we investigated TS-1 by second crystal modification under microwave and conventional conditions. The optimum modification time by microwave is 4 hours and show better performance than conditional methods.