物理化学学报 >> 1997, Vol. 13 >> Issue (03): 196-199.doi: 10.3866/PKU.WHXB19970302

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LiCl/γ-Al2O3的7Li MAS NMR研究

王凯旋,杨夏万,赵璧英,谢有畅,孙平川,门爱菊   

  1. 北京大学物理化学研究所，北京 100871|南开大学高分子化学研究所，天津 300071
  • 收稿日期:1996-11-29 修回日期:1996-12-19 发布日期:1997-03-15
  • 通讯作者: 赵璧英

7Li MAS NMR Studies on LiCl/γ-Al2O3

Wang Kai-Xuan,Yang Xia-Wan,Zhao Bi-Ying,Xie You-Chang,Sun Ping-Chuan,Men Ai-Ju   

  1. Institute of Physical Chemistry,Peking University,Beijing 100871|Institute of Polymer Chemistry,Nankai University,Tianjin 300071
  • Received:1996-11-29 Revised:1996-12-19 Published:1997-03-15
  • Contact: Zhao Bi-Ying

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摘要：

A Series of LiCl/γ-Al2O3 samples were prepared by mixing and then heating at 400℃ for 30 hours. 7Li MAS NMR was used to investigated their structures. The 7Li MAS NMR signal of LiCl in the dispersion phase was observed for the first time, and its chemical shift was at 0.25ppm. After the dispersion threshold of LiCl on γ-Al2O3 was achieved, the 7Li signal in the crystalline phase LiCl appears at -1.01ppm and its intensity increases with the increasing in LiCl loading. From the 2D nutation NMR spectra, it can be seen that the electric field gradient surrounding the lithium nuclei in the dispersion state is larger and so the quadrupole interaction is stonger than that in the crystalline state. The dispersion threshold indicated by NMR is in agreement with that deduced from XRD, which is about 0.136gLiCl/gγ-Al2O3.

关键词: LiCl/γ-Al2O3, 自发单层分散, 固体NMR, 二维章动NMR谱, 四极相互作用

Key words: LiCl/&gamma, -Al2O3, Sponteneous monolayer dispersion, Solid state NMR, 2D nutation NMR spectra, Qudrupole interaction