Speciation and siting of divalent transition metal ions in silicon-rich zeolites. An FTIR study

0511976 - ÚFCH JH 2020 RIV US eng J - Článek v odborném periodiku
Lemishka, Mariia - Dědeček, Jiří - Mlekodaj, Kinga - Sobalík, Zdeněk - Sklenák, Štěpán - Tabor, Edyta
Speciation and siting of divalent transition metal ions in silicon-rich zeolites. An FTIR study.
Pure and Applied Chemistry. Roč. 91, č. 11 (2019), s. 1721-1732. ISSN 0033-4545. E-ISSN 1365-3075
Grant CEP: GA ČR(CZ) GA17-00742S
Institucionální podpora: RVO:61388955
Klíčová slova: Brønsted acid * cobalt * infrared * manganese * nickel * ssc-2018 * transition-metal catalysis * zeolites
Obor OECD: Physical chemistry
Impakt faktor: 1.919, rok: 2019
Způsob publikování: Open access s časovým embargem

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. For more information, please visit: http://creativecommons.org/licenses/by-nc-nd/4.0/ 2019. Speciation and location of Co 2+ , Mn 2+ and Ni 2+ in the extraframework positions of the dehydrated zeolite matrix of ferrierite structure were studied in detail using FTIR spectroscopy of antisymmetric T-O-T vibrations of the zeolite framework. Me 2+ferrierites were prepared by the ion exchange of the NH 4 and Na-zeolite forms and by impregnation of the NH 4 form. Bare Me 2+ occupies all three known cationic sites in dehydrated cationic zeolite. The wavenumbers of bands of individual cations in individual sites were identified. At low Me 2+ loadings (Me 2+ /Al < 0.15), Me 2+ replaces two protonic sites and exclusively bare Me 2+ is present in dehydrated samples. Sets of such samples were employed for the estimation of extinction coefficients of Co 2+ , Mn 2+ and Ni 2+ in cationic sites. These coefficients differ for individual cations but are the same for a cation at different sites. Ion exchange to the NH 4 form allows preparation of samples with maximum possible loading of bare Me 2+ only for Co 2+ . In the case of Mn 2+ , exchange to the Na-parent zeolite or impregnation is required for this purpose while samples with maximum loading by bare Ni 2+ can be prepared only by impregnation.
Trvalý link: http://hdl.handle.net/11104/0302209