An NMR Scale for Measuring the Base Strength of Solid Catalysts with Pyrrole Probe: A Combined Solid-State NMR Experiment and Theoretical Calculation Study

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	An NMR Scale for Measuring the Base Strength of Solid Catalysts with Pyrrole Probe: A Combined Solid-State NMR Experiment and Theoretical Calculation Study
	Yi, Xianfeng 1,2; Li, Guangchao 1,2; Huang, Ling 1; Chu, Yueying 1; Liu, Zhiqiang 1,2; Xia, Hongqiang 1; Zheng, Amain 1; Deng, Feng 1
刊名	JOURNAL OF PHYSICAL CHEMISTRY C
	2017-02-23
卷号	121 期号:7 页码:3887-3895
英文摘要	Pyrrole has been employed as an NMR probe molecule to determine the base strength of solid catalytic materials; however, the quantitative correlation between the H-1 chemical shift of adsorbed pyrrole and the intrinsic base strength of solid catalysts is still lacking in the previous work. Here, solid-state NMR experiments and density functional theory (DFT) calculations were employed to explore the adsorption structures and H-1 chemical shifts of adsorbed pyrrole molecules over the zeolites with varied base strengths. Based on a generic 8T zeolite ((SiH3)(3)-Si-X-Si-O-(SiH3)(3), X = O or NH), various calculated models with different Si H bond lengths were constructed to represent the basic sites with varied strengths and used to predict the pyrrole adsorption structures as well as the H-1 chemical shifts. The solid-state NMR experimental results demonstrated that a larger H-1 chemical shift of adsorbed pyrrole corresponds to a stronger basic site on solid catalysts. A linear correlation between the H-1 chemical shift of adsorbed pyrrole and the proton affinity (PA) value of solid bases was theoretically derived, which is independent of the basic central atoms (e.g., O or N). In combination with the available H-1 MAS NMR experimental data, it is conclusive that pyrrole could be used as a probe to quantitatively characterize the intrinsic basicity of various solid catalysts, and the H-1 chemical shift threshold for superbasicity is 10.0 ppm. In addition, the influence of confinement effect on the adsorption structures and H-1 chemical shifts of pyrrole over basic catalysts was investigated as well.
WOS标题词	Science & Technology ; Physical Sciences ; Technology
类目[WOS]	Chemistry, Physical ; Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary
研究领域[WOS]	Chemistry ; Science & Technology - Other Topics ; Materials Science
关键词[WOS]	NUCLEAR-MAGNETIC-RESONANCE ; ACID CATALYSTS ; CHEMICAL-SHIFT ; ZEOLITE-Y ; P-31 NMR ; BECKMANN REARRANGEMENT ; SURFACE BASICITY ; 1ST PRINCIPLES ; H/D EXCHANGE ; SPECTROSCOPY
收录类别	SCI
语种	英语
WOS记录号	WOS:000394924800025
内容类型	期刊论文
源URL	[http://ir.wipm.ac.cn/handle/112942/10025]
专题	武汉物理与数学研究所_磁共振应用研究部
作者单位	1.Chinese Acad Sci, Natl Ctr Magnet Resonance Wuhan, Wuhan Inst Phys & Math, State Key Lab Magnet Resonance & Atom & Mol Phys, Wuhan 430071, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Yi, Xianfeng,Li, Guangchao,Huang, Ling,et al. An NMR Scale for Measuring the Base Strength of Solid Catalysts with Pyrrole Probe: A Combined Solid-State NMR Experiment and Theoretical Calculation Study[J]. JOURNAL OF PHYSICAL CHEMISTRY C,2017,121(7):3887-3895.
APA	Yi, Xianfeng.,Li, Guangchao.,Huang, Ling.,Chu, Yueying.,Liu, Zhiqiang.,...&Deng, Feng.(2017).An NMR Scale for Measuring the Base Strength of Solid Catalysts with Pyrrole Probe: A Combined Solid-State NMR Experiment and Theoretical Calculation Study.JOURNAL OF PHYSICAL CHEMISTRY C,121(7),3887-3895.
MLA	Yi, Xianfeng,et al."An NMR Scale for Measuring the Base Strength of Solid Catalysts with Pyrrole Probe: A Combined Solid-State NMR Experiment and Theoretical Calculation Study".JOURNAL OF PHYSICAL CHEMISTRY C 121.7(2017):3887-3895.