摘要
以介孔分子筛AlMSU-Y为载体,钛酸四丁酯、二氯二茂钛、四氯化钛为钛源,采用合成后嫁接法合成了3种Ti-AlMSU-Y介孔分子筛样品.用傅立叶变换红外光谱(FT-IR)、X射线粉末衍射(XRD)、N_2吸附-脱附、固体核磁(MAS NMR)、紫外-可见漫反射(UV-Vis)和能谱(EDS)进行了表征,并以环己醇氧化反应考察了样品的催化性能.实验结果表明,样品Ti-AlMSU-Y仍保持了基体AlMSU-Y介孔孔道结构,钛原子进入分子筛骨架且以骨架四面体钛的形式存在,同时分子筛中非骨架铝的含量相对减少.在环己醇氧化反应中,骨架四面体Ti和骨架四面体Al存在明显的协同作用,表现出较高的催化活性.3种Ti-AlMSU-Y样品中,以钛酸四丁酯为钛源制得的样品Ti(z)-AlMSU-Y对环己醇的催化活性最好,在80℃反应24 h,环己醇转化率为43.1%,环己酮选择性为100%.
Three Ti-A1MSU-Y mesoporous molecular sieves were successfully synthesized by a post-grafting method using the tetrabutyl titanate, bi-cyclopentadienyl titanium dichloride and titanium tetrachloride as the Ti source and the mesoporous molecular sieves as the support. The samples were characterized by FT-IR, XRD, N2 adsorption- desorption techniques, M_AS NMR, UV-Vis and EDS respectively. The catalytic behaviors of samples were measured through oxidation of cyclohexanol. Compared to the A1MSU-Y sieve, the resulting samples Ti-A1MSU-Y remained the original mesoporous structure with a smaller specific BET surface area and volume of pores. The UV-Vis and 27A1 MAS NMR spectra indicated the existence of tetrahedral titanium （IV） and tetrahedral aluminum（IV） in framework sites, and the content of oetahedral aluminium decreases when Ti atoms were grafted onto the inter-surface of A1MSU-Y simultaneously. All Ti-A1MSU-Y catalysts showed significant activity in oxidation of cyclohexanol due to cooperative action of Ti（ IV ） and A1 （IV）, and Ti（z）-A1MSU-Y with higher Ti/A1 molar ratio is better catalytic activity than Ti （m）-A1MSU-Y and Ti （y）-A1MSU-Y. More importantly, the conversion of cyclohexanol reaches 43.05%and the selectivity of cyclohexanone comes to 100% after 24 h at 80 ℃.
出处
《复旦学报（自然科学版）》
CAS
CSCD
北大核心
2012年第5期603-607,共5页
Journal of Fudan University：Natural Science
基金
安阳市科技攻关资助项目(2010097)
