caa a22 4500 378862790 CHVBK 20180305123350.0 cr unu---uuuuu 161128e20031201xx s 000 0 eng 10.1524/zpch.217.12.1613.20478 doi (NATIONALLICENCE)gruyter-10.1524/zpch.217.12.1613.20478 Influence of Cation Exchange on the 27Al-NMR Spectra of Zeolites [Elektronische Daten] [W. Masierak, T. Emmler, Gerd Buntkowsky, A. Gutsze] The influence of cation exchange on the 27Al-NMR spectra of NaA-zeolites has been studied by 27Al-MAS- and MQ-MAS-Solid State-NMR. From the 27Al-spectra a characterization of the different Al sites in the A zeolites according to their chemical environment and the structural changes on the aluminosilicate network caused by the cation exchange are obtained. It is found that the exchange with cations with smaller ion-radius cause stronger distortions of the 27Al-NMR-spectra than exchange with larger cations like Ba2+. Employing MQ-MAS spectroscopy these distortions are revealed as second order quadrupolar effects for the smaller cations and as a combination of chemical shift and second order quadrupolar interaction for the Ba cation. These changes of the quadrupolar coupling are interpreted numerically via calculations of the lowering of the symmetry of the EFG tensor. Finally it is found that the exchange with divalent cations leads to distortions of the zeolitic framework and the formation of an extra-framework aluminum. To the best of our knowledge this is for the first time that evidence for the production of extra frame work aluminum by pure cation exchange without any thermal treatment has been found in type A zeolites. © 2003 Oldenbourg Wissenschaftsverlag GmbH Thermodynamics & statistical physics nationallicence Laboratory techniques, experiments nationallicence Physical chemistry nationallicence Masierak W. aut Emmler T. aut Buntkowsky Gerd aut Gutsze A. aut Zeitschrift für Physikalische Chemie/International journal of research in physical chemistry and chemical physics Oldenbourg Wissenschaftsverlag GmbH 217/12/2003(2003-12-01), 1613-1626 0044-3336 217:12/2003<1613 2003 217 zpch https://doi.org/10.1524/zpch.217.12.1613.20478 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1524/zpch.217.12.1613.20478 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Masierak W. aut NATIONALLICENCE 700 1- Emmler T. aut NATIONALLICENCE 700 1- Buntkowsky Gerd aut NATIONALLICENCE 700 1- Gutsze A. aut NATIONALLICENCE 773 0- Zeitschrift für Physikalische Chemie/International journal of research in physical chemistry and chemical physics Oldenbourg Wissenschaftsverlag GmbH 217/12/2003(2003-12-01), 1613-1626 0044-3336 217:12/2003<1613 2003 217 zpch CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter