La骨架负载中孔分子筛的合成与表征

Synthesis and Characterization of La-MCM-41 Mesoporous Molecular Sieves with La Skeleton Adulteration

通过水热晶化法成功合成了骨架负载镧的中孔分子筛La-MCM-41,并用XRD、IR、Raman图谱进行表征,XRD图谱表明合成样品为中孔分子筛,IR、Raman图谱表明镧进入了分子筛骨架。同时考察了温度和硅源对分子筛合成的影响,以硅酸钠为硅源时,100℃为最佳合成温度,以正硅酸乙酯为硅源时,最佳合成温度为120℃;在相同温度下,以硅酸钠为硅源有利于形成中孔物相,且结晶度较好,以正硅酸乙酯为硅源,结晶度较低,不易形成中孔物相。

CTMAB-templated mesoporous molecular sieves with La skeleton adulteration were synthesized under hydrothermal conditions. The as-synthesized molecular sieves have small angle regions diffraction peaks in their XRD patterns corresponding to the mesoporous structures. And their IR spectra and Raman spectra show that the as-synthesized samples have characteristic bands of mesoporous MCM-41 molecular sieves, at the same time their IR spectra and Raman spectra of pure mesoporous molecular sieves are obviously different from those of La skeleton- adulterationed La-MCM-41 mesoporous molecular sieves. The effects of temperatures and silicon sources on La-MCM-41 were explored. The results indicate that when Na_2SiO_3 is used as silicon source, the best temperature is 100℃,while TEOS 120℃.At the same temperature, Na_2SiO_3, used as the silicon source, is helpful for forming mesoporous substance and the crystallites are better, but when using TEOS, it is difficult to yield mesoporous substance and the crystallites are low.