Research On The Preparation And Catalytic Activity Of Ti-MCM-41Molecular Sieve And The Synthesis Of DCP

H2O2was applied in the hydrothermally synthesis of Ti-MCM-41mesoporous molecular sieves. The structure and the form of titanium were characterized by means of XRD, UV-Vis and N2Adsorption. We investigated the effects of order of adding reagents, contents of alkali, temperature and time of alcohol eliminate, crystallization time on the structure of molecular sieves. The research result showed that the introduce of H2O2can control the hydrolysis rate of titanium source, which can match to the hydrolysis rate of silicon source, as a result the anatase was reduced. Alkali was necessary in the hydrolysis process, which can promote the hydrolysis of silicon and titanium. The experimental result indicated that optimum synthesis conditions were:alcohol eliminate temperature50℃, time of alcohol eliminate2h, crystallization time three days. Ti-MCM-41catalyst showed good catalytic activity in the process of epoxidation of propene, and catalytic activity was largely determined by the content of titanium. Under the optimum synthesis conditions, the utilization rate of cumene hydrogen peroxide can reach to55.1%, the selectivity for PO can reach to91.5%.The cumene hydroperoxide (CHP) was used as oxidant, Ti-MCM-41catalyst was applied in the process of epoxidation of propene. We inspected the mass space velocity, the reaction temperature and propene/CHP molar ratio. The experimental results showed that optimum reaction conditions were:the mass space velocity6h-1, reaction temperature90～100℃propene/CHP molar ratio4:1. Under the optimum reaction conditions, the catalyst showed good catalytic activity and stability in30h, the selectivity for PO can remain at90%, the conversion of CHP can remain at95%, and the utilization rate CHP can reach to55%.The dimethylbenzyl alcohol was produced in the process of epoxidation of propene, which can be used to synthesis DCP. Under the action of perchloric acid, the DCP was synthesized with dimethylbenzyl alcohol and CHP. Its purity can reach to97.89%after neutralization, extraction, vacuum distillation, freezing crystallization, and the yield of DCP can reach to74.1%. It will be a high atom economy process if combine the epoxidation of propene with the synthesis of DCP. After material equilibrium, with1kg Ti-MCM-41mesoporous molecular sieves, we can get0.249kg PO; when we produced1kg PO,7.35kg DCP was obtained.