用P轴承NMR探针分子吸附在地质石上测量的是什么?
Carlos Bornes1, Michael Fischer2,3, Jeffrey A Amelse1
1CICECO, Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
Journal of the American Chemical Society
|August 19, 2021
概括
三甲基氧化物 (TMPO) 不是一个可靠的酸度探测器. 新的研究表明它的NMR信号受到限制和二元化的影响, 不仅仅是酸位强度.
科学领域:
- 催化剂
- 材料科学
- 固态核磁共振光谱
背景情况:
- 了解石中的酸位对于催化是至关重要的.
- 三甲基氧化物 (TMPO) 是一种常见的酸度探测器.
- 最近的研究质疑TMPO NMR信号的解释.
研究的目的:
- 调查TMPO在HZSM-5热质中的相互作用.
- 重新评估使用TMPO作为布伦斯特德酸位点的探测器.
- 提供TMPO在石中的行为.
主要方法:
- 固态核磁共振光谱 (2D 1H-31P HETCOR).
- 密度函数理论 (DFT) 的计算.
- 一开始的分子动力学 (AIMD) 模拟.
- 有控制的TMPO加载实验.
主要成果:
- TMPO核磁共振信号受到热岩通道内的封闭效应的影响.
- 形成质子TMPO二极体,有助于观察到的NMR共振.
- 核磁共振的化学转移在很大程度上取决于原子在焦化物框架中的位置.
- 对于评估酸强度的TMPO NMR光谱的广泛接受解释受到质疑.
结论:
- 使用TMPO作为直接探测石中的布伦斯特德酸位强度是不可靠的.
- 隔离和客人互动显著影响TMPO NMR信号.
- 这项研究需要重新评估石特征的探针分子策略.
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