The analysis of the BAS OH band in zeolites

0558951 - ÚOCHB 2023 RIV NL eng J - Článek v odborném periodiku
Rubeš, Miroslav - Trachta, Michal - Vaculík, J. - Bulánek, R. - Bludský, Ota
The analysis of the BAS OH band in zeolites.
Microporous and Mesoporous Materials. Roč. 341, August (2022), č. článku 112052. ISSN 1387-1811. E-ISSN 1873-3093
Grant CEP: GA ČR(CZ) GA19-19542S
Výzkumná infrastruktura: IT4Innovations - 90070; CESNET II - 90042; CERIT-SC - 90085; CEMNAT II - 90103
Institucionální podpora: RVO:61388963
Klíčová slova: acidic zeolites * ab initio calculations * IR spectra
Obor OECD: Physical chemistry
Impakt faktor: 5.2, rok: 2022
Způsob publikování: Omezený přístup
https://doi.org/10.1016/j.micromeso.2022.112052

The zeolite frameworks (FER, TON, CHA, and IFR) with a large diversity of the IR band shapes in the OH stretching region were investigated by combined use of FT-IR spectroscopy and DFT calculations. The analysis of various isolated Brønsted acid sites was performed with a model based on Boltzmann weighted relative energies and OH frequencies obtained by the ω/r correlation method. This approach has recently been used to reveal the non-statistical incorporation of aluminum into the H-MOR framework. The model correctly predicts the band shapes of H-FER and H-TON zeolites in the free OH region of the FT-IR spectra. For H-CHA and H-IFR, however, the mutual BAS interactions cannot be ignored even for high Si/Al ratios, which renders the concept of isolated BAS inadequate. Thus, the periodic calculations of adsorption and catalytic properties of zeotype frameworks should always be carried out with extended models mimicking real heteroatom distribution in these materials.
Trvalý link: https://hdl.handle.net/11104/0332433