H-1/Al-27 TRAPDOR NMR studies on aluminum species in dealuminated zeolites
文献类型：期刊论文
| 作者 | Deng, F; Yue, Y; Ye, CH |
| 刊名 | SOLID STATE NUCLEAR MAGNETIC RESONANCE
 |
| 出版日期 | 1998 |
| 卷号 | 10期号:3页码:151-160 |
| 关键词 | H-1/Al-27 TRAPDOR Al-27 MAS NMR aluminum species zeolite |
| 英文摘要 | Aluminum species in several dealuminated zeolites (ultrastable HY, HZSM-5 and mordenite) were investigated in detail by means of the newly introduced H-1/Al-27 TRAPDOR method in combination with Al-27 MAS NMR, and the quadrupole coupling constants (Q(CC)s) for aluminum atoms associated with these species were obtained. A signal at ca. 6.8 ppm, due to water molecules adsorbed on Lewis acid sites, was observed in the H-1 MAS spectra for all the three zeolites. The TRAPDOR NMR provides direct evidence that there is a strong interaction between the adsorbed water molecules and the aluminum atoms of the Lewis-acid sites. The Q(CC) values for this aluminum species of 8.3, 6.7 and 11.3 MHz were determined from the TRAPDOR profiles for the ultrastable HY, HZSM-5 and mordenite zeolites, respectively. The Q(CC)s calculated from the TRAPDOR curves are usually larger than 10 MHz for both Bronsted-acid sites (SiOHAI) and non-framework aluminum species in the three zeolites. Three narrow peaks at 54, 30 and 0 ppm are separately superimposed on a broad hump in the Al-27 MAS spectra of the three dehydrated zeolites, while the latter is associated with the 'NMR invisible' Al. The NMR experimental results suggest that the three kinds of aluminum species (non-framework aluminum species, Bronsted-and Lewis-acid sites) are all responsible for the resonance of the broad hump in dehydrated zeolites, which makes it difficult to explain the Al-27 MAS spectra. Fortunately, the TRAPDOR NMR provides a direct method for individually studying different aluminum species with large Q(CC)s via their dipolar coupling to nearby proton nuclei. Published by Elsevier Science B.V. |
| WOS标题词 | Science & Technology ; Physical Sciences ; Technology |
| 类目[WOS] | Chemistry, Physical ; Physics, Atomic, Molecular & Chemical ; Physics, Condensed Matter ; Spectroscopy |
| 研究领域[WOS] | Chemistry ; Physics ; Spectroscopy |
| 关键词[WOS] | NUCLEAR-MAGNETIC-RESONANCE ; ACID SITES ; RESOLUTION ; MAS ; QUADRUPOLAR ; H-ZSM-5 ; SPECTRA ; SOLIDS ; HZSM-5 ; HY |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000072727800006 |
| 公开日期 | 2015-12-01 |
| 源URL | [http://ir.wipm.ac.cn/handle/112942/8278]  |
| 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 | Acad Sinica, Wuhan Inst Phys, Lab Magnet Resonance & Atom & Mol Phys, Wuhan 430071, Peoples R China |
| 推荐引用方式 GB/T 7714 | Deng, F,Yue, Y,Ye, CH. H-1/Al-27 TRAPDOR NMR studies on aluminum species in dealuminated zeolites[J]. SOLID STATE NUCLEAR MAGNETIC RESONANCE,1998,10(3):151-160. |
| APA | Deng, F,Yue, Y,&Ye, CH.(1998).H-1/Al-27 TRAPDOR NMR studies on aluminum species in dealuminated zeolites.SOLID STATE NUCLEAR MAGNETIC RESONANCE,10(3),151-160. |
| MLA | Deng, F,et al."H-1/Al-27 TRAPDOR NMR studies on aluminum species in dealuminated zeolites".SOLID STATE NUCLEAR MAGNETIC RESONANCE 10.3(1998):151-160. |
入库方式： OAI收割
来源：武汉物理与数学研究所
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