MCM-41中孔分子筛的结构和性能研究

STRUCTUER AND PROPERTY STUDIES OF MESOPOROUS MCM-41 MOLECULAR SIEVE

用Ｘ射线衍射仪、红外光谱仪、固体魔角旋转核磁仪、电子自旋共振仪等表征手段， 考察了ＭＣＭ－４１ 中孔分子筛的结构和性能。结果表明， ＭＣＭ－４１ 分子筛的结构不同于一般微孔分子筛和无定形硅（铝） 胶，其孔墙结构类似于无定形硅酸盐的局域原子排布，反映在ＸＲＤ和２９ＳｉＭＡＳＮＭＲ谱上，孔壁分布均匀有序，但整体结构缺乏规整的长程序三维空间原子排布。酸性表征表明， ＭＣＭ－４１ 中孔分子筛酸性中等， 较Ｙ 分子筛弱， 在酯化、烷基化等反应中的催化作用也体现出这一点。

By means of XRD,IR,solid state MAS NMR,ESR and other techniques,the structure and properties of mesoporous molecular sieve material MCM 41 were studied.Results indicated that structure of MCM 41 molecular sieve is different from that of ordinary microporous zeolite molecular sieves and amorphous aluminosilicates.The channel walls show a local atomic structure similar to that of amorphous silica,which can be characterized by XRD and 29 Si MAS NMR spectra,whereas these mesoporous channels are uniformly arranged,that is to say,MCM 41 does not have regular long range order atomic arrangement in three dimensions,short of strict crystallographic order on the atomic level,but the local atomic arrangement is different from that in amorphous silica.Additionally,MCM 41 shows a medium acidity,which can be detected in the reactions of esterification and alkylation.