Local Structure of Cationic Sites in Dehydrated Zeolites Inferred from Al-27 Magic-Angle Spinning NMR and Density Functional Theory Calculations. A Study on Li-, Na-, and K-Chabazite

Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216275%3A25310%2F16%3A39901499" target="_blank" >RIV/00216275:25310/16:39901499 - isvavai.cz</a>
Result on the web
<a href="http://dx.doi.org/10.1021/acs.jpcc.6b04391" target="_blank" >http://dx.doi.org/10.1021/acs.jpcc.6b04391</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1021/acs.jpcc.6b04391" target="_blank" >10.1021/acs.jpcc.6b04391</a>

Result language
angličtina
Original language name
Local Structure of Cationic Sites in Dehydrated Zeolites Inferred from Al-27 Magic-Angle Spinning NMR and Density Functional Theory Calculations. A Study on Li-, Na-, and K-Chabazite
Original language description
High-resolution Al-27 magic-angle spinning (MAS) NMR spectroscopy of dehydrated M-forms (M = Li, Na, and K) of chabazite in tandem with density functional theory calculations are employed to study the quadrupolar interaction of Al-27 nuclei in dehydrated zeolites and to understand the corresponding high-resolution Al-27 MAS NMR spectra. We show that the broadening of the Al-27 NMR signal in dehydrated zeolites occurs predominantly because of the deformation of the local structure of AlO4- tetrahedra caused by the binding of M+ to the zeolite framework. This deformation increases with the decreasing diameter of the cations from K+ to Li+. The influence of water in hydrated zeolites is limited only to prevent a strong coordination of the M+ cation to O atoms of the AlO4- tetrahedron, but there is no "averaging" effect concerning the local electrostatic field due to molecular motion of water molecules. Our results show that the Al-27 NMR parameters in dehydrated zeolites can be calculated accurately enough to allow the description of the local structure of AlO4- tetrahedra in dehydrated zeolites and to infer the local structure of the sites accommodating the extraframework M+ cations.
Czech name
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Czech description
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Type
J<sub>x</sub> - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)
CEP classification
CF - Physical chemistry and theoretical chemistry
OECD FORD branch
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Project
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Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year
2016
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

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