非离子表面活性剂体系Ti-MWW分子筛的合成

以哌啶为模板剂,添加非离子表面活性剂吐温系列,水热条件下合成Ti-MWW分子筛。采用XRD、UV-Vis、SEM和BET等手段对分子筛进行表征。以正己烯环氧化反应作探针反应,评价分子筛的催化性能。结果表明,添加非离子表面活性剂种类不同时,催化剂的催化性能有所差异。m(吐温60)∶m(SiO_2)=0.015,分子筛的催化性能优于传统法投料配比合成得到的催化剂,正己烯转化率达72.7%,产物环氧己烷选择性近100%。初步尝试解释了非离子表面活性剂系列对催化剂催化性能影响的原因及其作用机理。

Synthesis of Titanosilicate Ti-MWW with nonionic surfactants

Under hydrothermal condition, Titanosilicate Ti-MWW was synthesized using piperidine （PI） as the template in the presence of nonionic surfactants Tween. The samples were characterized by XRD, UV-Vis, SEM and BET techniques. The catalytic properties of the catalysts were investigated using the epoXidation of 1-hexene as the probe reaction. The results showed that Ti-MWW with Tween 60 catalysts Showed higher catalytic activity than Ti-MWW in the epoxidation of 1-hexene with hydrogen peroxide. 1-Hexene conversion of 72.7% and the selectivity to epoxy hexane of nearly 100% were obtained, respectively, under the condition of Tween 60/SiO2 mass ratio of 0.015. It was also found that the addition of Tween 20,Tween 40 and Tween 80 could not improve the catalytic performance of Ti-MWW zeolite. The mechanism and influencing reason of Tween to catalytic performance of Titanosilicate Ti-MWW were tentatively explained.