新型液固相同晶取代法制备Ti-β沸石  

A Novel Liquid-solid Isomorphous Substitution Route for Preparing Zeolite Ti-β

作　　者：周炜[1] 淳远[1] 须沁华[1] 王程[1] 董家騄[1] 

机构地区：[1]南京大学化学系,南京210093

出　　处：《高等学校化学学报》2004年第1期16-20,共5页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金 (批准号 :3 445 65 46)资助

摘　　要：采用以 Ti(SO4 ) 2 液固相同晶取代 H-β沸石的后合成新路线制备 Ti-β沸石 ,并对制得的样品进行了XRD,IR,Raman,UV-Vis,XPS和正己烷吸附等表征以及催化活性的测定 .发现经过质量分数为 3 0 %的Ti(SO4 ) 2 水溶液适当改性后得到的 Ti-β沸石具有良好的催化性能 .Raman和 UV-Vis光谱及正己烷吸附的结果表明 ,后合成路线制得的 Ti-β样品仅存在很少量的骨架外的 Ti物种 .UV-Vis光谱在 2 2 0 nm处的强吸收峰和骨架在 960 cm- 1 处的红外吸收峰均证明在沸石骨架中存在四配位 Ti原子 .通过液固相同晶取代法得到的 Ti-β沸石对环己烯与 3 0 % H2 O2 的环氧化反应具有很高的催化活性 ,由于样品中仍存在酸性位 ,因此其反应产物主要是环己烯环氧化后的醇解及水解产物 .A novel convenient method, liquid-solid isomorphous substitution(LSIS) of Ti(SO 4) 2, was used to post-synthesize titanium beta(Ti-β) zeolite in this paper. The prepared Ti-β zeolites were characterized by XRD, IR, Raman, UV-Vis, XPS, adsorption of hexane, as well as catalytic testing. Ti-β zeolite prepared from 30% Ti(SO 4) 2 showed good catalytic properties, while excessive usage of Ti(SO 4) 2 rendered an inferior catalyst. The results from Raman, UV-Vis and adsorption of hexane indicate that fewer extra-framework Ti species were formed on these modified samples. The presence of the strong absorption band around 220 nm in UV-Vis spectra and the appearance of the band around 960 cm -1 in IR spectra demonstrate that the tetrahedrally coordinated Ti-atoms exist in the framework of Ti-containing zeolites. These Ti-β zeolites prepared by LSIS method were active in the epoxidation of olefin with H 2O 2, and the main products are the alcoholysis and hydrolysis product of the epoxide, due to the stronger acidic sites remained on the catalysts. The significantly higher activity can be achieved on these Ti-β zeolites in epoxidation of cyclohexene with respect to conventional TS-1 zeolite.

关 键 词：液固相同晶取代法 制备 Ti-β沸石 硫酸钛 环氧化 中孔钛硅沸石 过氧化氢 

分 类 号：TQ424.25[化学工程]