增强的固态NMR对应光谱四极原子核使用动态核极化
Daniel Lee1, Hiroki Takahashi, Aany S L Thankamony
1Laboratoire de Chimie Inorganique et Biologique, UMR-E CEA/UJF-Grenoble, Institut Nanosciences et Cryogénie, France.
Journal of the American Chemical Society
|October 26, 2012
概括
动态核极化 (DNP) 显著增强固态NMR光谱学 (SSNMR),使得快速,界面选择性研究的中孔. 这一突破允许在催化材料中的四极核的详细原子尺度结构确定.
科学领域:
- 固态NMR光谱学 固态NMR光谱学
- 材料科学 材料科学 材料科学
- 表面化学 表面化学
背景情况:
- 四极核对传统的固态NMR光谱学构成挑战,原因是交叉极化和二极再合效率低.
- 半孔是一种具有工业应用的先进材料,需要详细的结构特征.
- 界面选择性结构信息对于理解材料特性和性能至关重要.
研究的目的:
- 通过使用动态核极化 (DNP) 来证明固态NMR光谱 (SSNMR) 的灵敏度增强技术.
- 在半孔中记录四极核 ((27) Al) 的界面选择性的二极二极相关谱.
- 为了确定中孔中物种的原子尺度结构和界面协调.
主要方法:
- 利用动态核极化 (DNP) 来提高固态NMR光谱学 (SSNMR) 的灵敏度.
- 在半孔上进行了界面选择性 (27) Al-(27) Al 二维二极相对应实验.
- 在低温下进行的实验 (约. 103 K) 和 9.4 T 的磁场.
主要成果:
- 与传统的SSNMR相比,节省了4-5个数量级的时间.
- 成功记录了界面选择性的 (27) Al-(27) Al 2D二极相对应谱.
- 观察并确定了五协调在跨界四和六协调物种的作用.
- 在短短4小时内获得了关键的结构信息,在标准条件下这是不可能的.
结论:
- 用DNP增强的SSNMR克服了研究四极核的局限性.
- 这种技术使得像中孔这样的材料中的界面物种能够快速,原子级的结构确定.
- 开辟了SSNMR应用于催化材料和其他具有四极核的系统的新途径.
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