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Effect of Al-Si-Al and Al-Si-Si-Al Pairs in the ZSM-5 Zeolite Framework on the Al-27 NMR Spectra. A Combined High-Resolution Al-27 NMR and DFT/MM Study

SYSNO ASEP	0322907
Document Type	J - Journal Article
R&D Document Type	Journal Article
Subsidiary J	Ostatní články
Title	Effect of Al-Si-Al and Al-Si-Si-Al Pairs in the ZSM-5 Zeolite Framework on the Al-27 NMR Spectra. A Combined High-Resolution Al-27 NMR and DFT/MM Study
Title	Efekt přítomnosti Al-O-Si-O-Al a Al-O-Si-O-Si-O-Al sekvencí v ZSM-5 zeolitovém skeletu na lokální geometrii AlO4- tetrahedru a 27Al NMR parametry byl vyšetřován za použití 27Al 3Q MAS NMR spektroskopie a DFT/MM výpočtu
Author(s)	Dědeček, Jiří (UFCH-W)_{RID, ORCID} Sklenák, Štěpán (UFCH-W)_{RID, ORCID, SAI} Li, Chengbin (UFCH-W) Wichterlová, Blanka (UFCH-W)_RID Gábová, Vendula (UFCH-W) Brus, Jiří (UMCH-V)_{RID, ORCID} Sierka, M. (DE) Sauer, J. (DE)
Source Title	Journal of Physical Chemistry C. - : American Chemical Society - ISSN 1932-7447 Roč. 113, č. 4 (2009), s. 1447-1458
Number of pages	12 s.
Language	eng - English
Country	US - United States
Keywords	zeolites ; ab-initio calculation ; MAS NMR
Subject RIV	CF - Physical ; Theoretical Chemistry
R&D Projects	1ET400400413 GA AV ČR - Academy of Sciences of the Czech Republic (AV ČR)
	IAA400400812 GA AV ČR - Academy of Sciences of the Czech Republic (AV ČR)
	KAN100400702 GA AV ČR - Academy of Sciences of the Czech Republic (AV ČR)
CEZ	AV0Z40400503 - UFCH-W (2005-2011)
	AV0Z40500505 - UMCH-V (2005-2011)
DOI	10.1021/jp8068333
Annotation	The effect of the presence of Al-O-Si-O-Al and Al-O-Si-O-Si-O-Al sequences in the ZSM-5 zeolite framework on the local geometry of AlO4- tetrahedra and the Al-27 NMR parameters was investigated employing Al-27 3Q MAS NMR spectroscopy and DFT/MM calculations. The presence of an At atom as a next-nearest (Al-O-Si-O-Al) and next-next-nearest (Al-O-Si-O-Si-O-Al) neighbor can significantly affect both the local geometry of AlO4- tetrahedra as well as Al-27 NMR isotropic chemical shift (up to 4 ppm). There is no systematic contribution of Al in Al-O-Si-O-Al or Al-O-(Si-O)(2)-Al chains to the Al-27 isotropic chemical shift, and not even the direction can be predicted without explicit DFT calculations.
Workplace	J. Heyrovsky Institute of Physical Chemistry
Contact	Michaela Knapová, michaela.knapova@jh-inst.cas.cz, Tel.: 266 053 196
Year of Publishing	2009

Number of the records: 1