Structure of framework aluminum Lewis sites and perturbed aluminum atoms in zeolites as determined by 27Al{1H} REDOR (3Q) MAS NMR spectroscopy and DFT/molecular mechanics

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388955%3A_____%2F15%3A00439638" target="_blank" >RIV/61388955:_____/15:00439638 - isvavai.cz</a>

Alternative codes found

RIV/61389013:_____/15:00439638

Result on the web

<a href="http://dx.doi.org/10.1002/anie.201409635" target="_blank" >http://dx.doi.org/10.1002/anie.201409635</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1002/anie.201409635" target="_blank" >10.1002/anie.201409635</a>

Result language

angličtina

Original language name

Structure of framework aluminum Lewis sites and perturbed aluminum atoms in zeolites as determined by 27Al{1H} REDOR (3Q) MAS NMR spectroscopy and DFT/molecular mechanics

Original language description

Zeolites are highly important heterogeneous catalysts. Besides Br?nsted SiOHAl acid sites, also framework AlFR Lewis acid sites are often found in their H-forms. The formation of AlFR Lewis sites in zeolites is a key issue regarding their selectivity inacid-catalyzed reactions. The local structures of AlFR Lewis sites in dehydrated zeolites and their precursors??perturbed AlFR atoms in hydrated zeolites?were studied by high-resolution MAS NMR and FTIR spectroscopy and DFT/MM calculations. Perturbed framework Al atoms correspond to (SiO)3AlOH groups and are characterized by a broad 27Al NMR resonance (?i=59?62?ppm, CQ=5?MHz, and ?=0.3?0.4) with a shoulder at 40?ppm in the 27Al?MAS?NMR spectrum. Dehydroxylation of (SiO)3AlOH occurs at mild temperaturesand leads to the formation of AlFR Lewis sites tricoordinated to the zeolite framework. Al atoms of these (SiO)3Al Lewis sites exhibit an extremely broad 27Al?NMR resonance (?i67?ppm, CQ20?MHz, and ?0.1).

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

CI - Industrial chemistry and chemical engineering

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

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2015

Confidentiality

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

Name of the periodical

Angewandte Chemie - International Edition

ISSN

1433-7851

e-ISSN

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Volume of the periodical

54

Issue of the periodical within the volume

2

Country of publishing house

DE - GERMANY

Number of pages

5

Pages from-to

541-545

UT code for WoS article

000347238800026

EID of the result in the Scopus database

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