大颗粒廉价TS-1制备及其在KA油生产中应用

Preparation of large-particle-size low-cost titanium silicalite-1 and its application in KA oil production

分别以硅溶胶和三氯化钛(TiCl3)作为硅源与钛源、以四丙基溴化胺(TPABr)为模板剂,制备了一系列低成本的大颗粒钛硅分子筛(TS-1)。使用XRD,FTIR,UV-vis,SEM,N2吸附-脱附等技术对催化剂进行表征,研究了结晶温度和碱度对TS-1的结构与催化性能的影响。评估了催化剂对于环己烷氧化制备KA油(环己醇和环己酮)的催化活性,考察了不同氧化剂用量和催化剂用量下KA油的产率。结果表明:以TS-1-5为催化剂,在最佳反应条件下KA油的产率达到了23.0%,选择性为97.8%,催化剂在重复使用4次后的活性与结构没有发生明显变化。这种大颗粒的TS-1可以在10 min内通过自然沉降从反应体系中分离,而传统钛硅分子筛至少需要5 h。

A series of low-cost large-particle-size of titanium silicalite-1(TS-1)were synthesized by using silica sol and titanium trichloride(TiCl3)as the silicon and titanium resource,respectively,and using tetrapropylammonium bromide(TPABr)as the template.The catalysts were characterized by XRD,FTIR,UV-vis,SEM and N2 adsorption-desorption.Otherwise,the effects of crystallization temperature and alkalinity for structure and catalytic performance of TS-1 were also investigated.The TS-1 was employed as the catalyst for the preparation of KA oil(cyclohexanol and cyclohexanone)from cyclohexane oxidation,of which the influences of different amounts of oxidant and catalyst were systematically investigated.Under the optimized reaction conditions,the KA oil yield reached 23.0%with 97.8%selectivity to cyclohexane while the TS-1-5 was used as a catalyst.The catalyst exhibits stable activity and structure after the fourth run.The large particle TS-1 can be separated from the reaction system by natural sedimentation within 10 min,while the traditional TS-1 takes at least 5 h.