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

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389013%3A_____%2F16%3A00460633" target="_blank" >RIV/61389013:_____/16:00460633 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/61388955:_____/16:00460633

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

High-resolution 27Al 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 27Al nuclei in dehydrated zeolites and to understand the corresponding high-resolution 27Al MAS NMR spectra. We show that the broadening of the 27Al 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 27Al 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.

Název v anglickém jazyce

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

Popis výsledku anglicky

High-resolution 27Al 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 27Al nuclei in dehydrated zeolites and to understand the corresponding high-resolution 27Al MAS NMR spectra. We show that the broadening of the 27Al 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 27Al 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.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

CD - Makromolekulární chemie

OECD FORD obor

—

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2016

Kód důvěrnosti údajů

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

Název periodika

Journal of Physical Chemistry C

ISSN

1932-7447

e-ISSN

—

Svazek periodika

120

Číslo periodika v rámci svazku

26

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

10

Strana od-do

14216-14225

Kód UT WoS článku

000379457000039

EID výsledku v databázi Scopus

2-s2.0-84978027691