MCM-48分子筛的合成、XRD的表征及^(129)Xe核磁共振的研究

Synthesis of mesoporous molecular sieve MCM-48、X-ray diffraction and^(129)Xe NMR

用水热法合成了MCM - 48,并研究了MCM - 48分子筛结构 ,通过X射线衍射和12 9Xe核磁共振研究了其空间结构 ,确定了MCM - 48为Ia3d空间群的立体结构 .经过 5 6 0℃烧后的MCM - 48分子筛 ,空间群结构仍未改变 .与一维的MCM - 41分子筛比较 ,MCM - 48分子筛的核磁共振化学位移有两个峰 ,而且位移小 ,说明MCM - 48是立体结构 ,而且孔径也大于MCM - 41.

A cubic member of mesoporous molecular sieve M41S family with a three dimension structure was denoted as MCM-48. A cubic symmetry with an Ia3dspace group was determined by X-ray powder diffraction(XRD)for the as -synthesized and calcined MCM-48 material. The pore structure was unaffected by the local change of structure .The chemical shift in 129 Xe NMR Spectroscopy of adsorbed Xenon indicates that the MCM-48 is a cubic symmetry compared with MCM-41, one-dimensional pore channels. The pore of MCM-48 is bigger than that of MCM-41.