Ce-MCM-48立方介孔分子筛结构的光谱表征  

Spectroscopic Characterization of Structure of Cerium Incorporated MCM-48 Mesoporous Molecular Sieve

作　　者：金忠秀[1] 雍国平[1] 盛良全[1] 童红武[1] 苏庆德[1] 刘少民[1] 

机构地区：[1]中国科学技术大学化学与材料科学学院,安徽合肥230026

出　　处：《光谱学与光谱分析》2006年第3期484-487,共4页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金(20405013)资助项目

摘　　要：在碱性条件下,以混合模板剂pH调节水热合成了掺入铈的介孔分子筛Ce-MCM-48,并采用XRD,DRUV-Vis(紫外-可见漫反射),FTIR,XRF结合BET等测试手段对样品进行表征。实验结果表明,采用本方法所合成的掺铈介孔材料仍保持立方介孔的有序结构,同时适量的铈的掺入和pH调节使分子筛的有序性及吸附性能得到改善,晶胞参数增大,孔径更均一,孔壁增厚。从而可推出Ce-MCM-48的热稳定性、水热稳定性、催化活性及择形选择性可得到提高。掺入的铈以四配位状态高度分散在介孔的有序结构当中。红外光谱表明不同量的铈的掺入对骨架硅的各种振动扰动程度不同。Cerium incorporated MCM-48 molecular sieves have been hydrothermally synthesized using a mixed template and pH adjusting route The samples were characterized by various physicochemical methods, including X-ray diffraction, diffuse reflectance UV-Vis spectroscopy, FTIR spectroscopy, XRF spectroscopy, and nitrogen adsorption. These results reveal that cerium is incorporated in MCM-48 and it is in the form of well-dispersed tetra-coodinated cerium ion. The proper concentration of cerium and adjusting pH can keep Ce-MCM-48 with higher specific surface area , larger unit-cell parameter, narrower pore-size distribution, and thicker pore wall than those of MCM-48. These deduce higher activity, and better selectivity, thermal stability and hydrothermal stability than those of MCM-48. The concentration of Ce incorporated in MCM-48 affects the vibration of the framewoke Si of molecular sieves.

关 键 词：CE MCM-48 光谱表征 立方介孔分子筛 

分 类 号：O643[理学—物理化学]