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 crystallme 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.
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 crystallme 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.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
1997年第3期196-199,共4页
Acta Physico-Chimica Sinica
基金
国家自然科学基金
南开大学功能高分子国家重点实验室资助
关键词
活性组分
自发单层分散
载体表面
氯化锂
氧化铝
LiCl/γ-Al_2O_3, Sponteneous monolayer dispersion, Solid state NMR, 2D nutation NMR spectra, Qudrupole interaction
