Combined DFT theoretical calculation and solid-state NMR studies of Al substitution and acid sites in zeolite MCM-22
文献类型：期刊论文
| 作者 | Zheng, AM; Chen, L; Yang, J; Zhang, MJ; Su, YC; Yue, Y; Ye, CH; Deng, F |
| 刊名 | JOURNAL OF PHYSICAL CHEMISTRY B
 |
| 出版日期 | 2005-12-29 |
| 卷号 | 109期号:51页码:24273-24279 |
| 英文摘要 | The distributions of Bronsted acidic protons and their acid strengths in zeolite H-MCM-22 have been characterized by density functional theory (D]FT) calculations as well as magic angle spinning (MAS) NMR experiments. The embedded scheme (ONIOM) that combines the quantum mechanical (QM) description of active sites and semiempirical AM1 treatment of the neighboring environment was applied to predict the C aluminum substitution mechanism and proton affinity (PA), as well as adsorption behaviors of acetone and trimethylphosphine oxide (TMPO) onto the zeolite. Our theoretical results indicate that the A1 substitution takes place in the order of A11-OH-Si2 > A18-OH-Si8 > A15-OH-SiT The DFr theoretical and NMR experimental results suggest that the acid strength of the three Bronsted acid sites in H-MCM-22 zeolite is slightly lower than that of H-ZSM-5 zeolite and the accessible Bronsted acidic protons most likely reside in both the supercages (at the A18-OH-Si8 and A11-OH-Si2 sites) and external surface pocket (at the A18OH-Si8 site) rather than in the sinusoidal channels (A15-OH-Si7), with the A11-OH-Si2 site having the strongest acid strength (as probed by TMPO). This may partially explain the special selectivity of acid-catalyzed reactions occurring inside the channels of H-MCM-22 zeolite. |
| WOS标题词 | Science & Technology ; Physical Sciences |
| 类目[WOS] | Chemistry, Physical |
| 研究领域[WOS] | Chemistry |
| 关键词[WOS] | DENSITY-FUNCTIONAL THEORY ; P-31 MAS NMR ; TRIMETHYLPHOSPHINE OXIDE ; STRUCTURAL-CHARACTERIZATION ; EXTERNAL SURFACE ; CHEMICAL-SHIFTS ; PROTON-TRANSFER ; PROBE MOLECULE ; XE-129 NMR ; SPECTROSCOPY |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000234259900011 |
| 公开日期 | 2015-07-28 |
| 源URL | [http://ir.wipm.ac.cn/handle/112942/4502]  |
| 专题 | 武汉物理与数学研究所_2011年以前论文发表（包括2011年） |
| 作者单位 | Chinese Acad Sci, Wuhan Inst Phys & Math, State Key Lab Magnet Resonance & Atom & Mol Phys, Wuhan 430071, Peoples R China |
| 推荐引用方式 GB/T 7714 | Zheng, AM,Chen, L,Yang, J,et al. Combined DFT theoretical calculation and solid-state NMR studies of Al substitution and acid sites in zeolite MCM-22[J]. JOURNAL OF PHYSICAL CHEMISTRY B,2005,109(51):24273-24279. |
| APA | Zheng, AM.,Chen, L.,Yang, J.,Zhang, MJ.,Su, YC.,...&Deng, F.(2005).Combined DFT theoretical calculation and solid-state NMR studies of Al substitution and acid sites in zeolite MCM-22.JOURNAL OF PHYSICAL CHEMISTRY B,109(51),24273-24279. |
| MLA | Zheng, AM,et al."Combined DFT theoretical calculation and solid-state NMR studies of Al substitution and acid sites in zeolite MCM-22".JOURNAL OF PHYSICAL CHEMISTRY B 109.51(2005):24273-24279. |
入库方式： OAI收割
来源：武汉物理与数学研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。