Effect of Al/Si Substitutions and Silanol Nests on the Local Geometry of Si and Al Framework Sites in Silicone-Rich Zeolites: A Combined High Resolution Al-27 and Si-29 NMR and Density Functional Theory/Molecular Mechanics Study

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388955%3A_____%2F09%3A00336493" target="_blank" >RIV/61388955:_____/09:00336493 - isvavai.cz</a>

Alternative codes found

RIV/61389013:_____/09:00336493

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Effect of Al/Si Substitutions and Silanol Nests on the Local Geometry of Si and Al Framework Sites in Silicone-Rich Zeolites: A Combined High Resolution Al-27 and Si-29 NMR and Density Functional Theory/Molecular Mechanics Study

Original language description

We employed Si-29 and Al-27 (3Q) magic-angle spinning (MAS) NMR spectroscopy and density functional theory/molecular mechanics (DFT/MM) calculations to investigate the effect of Al/Si substitutions and the presence of silanol nests on the Si-29 and Al-27NMR parameters as well as the local geometry Of SiO4 and AlO4- tetrahedra of the nearest and next-nearest neighboring Si and Al atoms. The silicon-rich zeolite of the chabazite structure (Si/Al 38) was chosen for this study as a representative model ofsilicon-rich zeolites since it exhibits a low number of distinguishable T sites. Our computational results show the following: (1) Al atoms can occupy three different crystallographic T sites in the framework of chabazite (Si/Al 38). This result is in agreement with two observed Al-27 NMR resonances. (II) An Al/Si substitution causes a downshift of the Si-29 chemical shift of the nearest neighboring Si atoms (Al-O-Si) by 4-11 ppm...

Czech name

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Czech description

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Type

J_x - 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

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>Z - Vyzkumny zamer (s odkazem do CEZ)

Publication year

2009

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Physical Chemistry C

ISSN

1932-7447

e-ISSN

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Volume of the periodical

113

Issue of the periodical within the volume

32

Country of publishing house

US - UNITED STATES

Number of pages

13

Pages from-to

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UT code for WoS article

000268661300059

EID of the result in the Scopus database

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