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Determination of Zn Speciation, Siting, and Distribution in Ferrierite Using Luminescence and FTIR Spectroscopy
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SYSNO ASEP 0542441 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title Determination of Zn Speciation, Siting, and Distribution in Ferrierite Using Luminescence and FTIR Spectroscopy Author(s) Olszówka, Joanna Elżbieta (UFCH-W) ORCID
Lemishka, Mariia (UFCH-W) RID, ORCID
Mlekodaj, Kinga (UFCH-W) RID, ORCID
Kubát, Pavel (UFCH-W) RID, ORCID, SAI
Rutkowska-Żbik, D. (PL)
Dědeček, Jiří (UFCH-W) RID, ORCID
Tabor, Edyta (UFCH-W) RID, ORCIDSource Title Journal of Physical Chemistry C. - : American Chemical Society - ISSN 1932-7447
Roč. 125, č. 17 (2021), s. 9060-9073Number of pages 14 s. Language eng - English Country US - United States Keywords Fourier transform infrared spectroscopy ; Ions ; Luminescence Subject RIV CF - Physical ; Theoretical Chemistry OECD category Physical chemistry R&D Projects GA17-00742S GA ČR - Czech Science Foundation (CSF) Method of publishing Limited access Institutional support UFCH-W - RVO:61388955 UT WOS 000648873500015 EID SCOPUS 85105028927 DOI 10.1021/acs.jpcc.1c00543 Annotation A methodology for the analysis of the siting of Zn2+ ions in extra-framework cationic sites of silicon-rich zeolite was developed and demonstrated on Zn-ferrierite samples (Si/Al 8.5, Zn/Al 0.04-0.33). This methodology is based on the FTIR spectroscopy of antisymmetric tetrahedral-octahedral-tetrahedral (T-O-T) vibrations of the zeolite framework perturbed by Zn2+ ions, combined with a complementary approach based on Zn2+ luminescence monitored by laser-induced time-resolved luminescence spectroscopy. Three vibration bands in the FTIR spectra of antisymmetric T-O-T vibrations of dehydrated zeolite reflect Zn2+ ligation in three extra-framework cationic sites of ferrierite zeolite. The band at 935 cm-1 corresponds to Zn2+ ions in the α-site of ferrierite, the band at 917 cm-1 correspondsto ions in β-site, and the band at 902 cm-1 correspondsto Zn2+ ions in the γ-site. The extinction coefficient for quantitative analysis of Zn2+ ions in cationic sites was estimated and exhibited the same value for Zn2+ cations in all cationic sites, ϵ = 49.1 ± 3.8 cm·μmol-1. In all Zn samples, Zn2+ siting in the β-site prevails, while Zn2+ ions in the γ-site are of low population or negligible. Time-resolved luminescence showed that bare Zn2+ ions in the extra-framework cationic sites can be distinguished from Zn2+ ions in ZnO by a decay time which is several magnitudes longer and a high sensitivity for quenching. The luminescence spectrum of Zn-ferrierites is composed of three bands at 545, 480, and 425 nm attributable to Zn2+ ions in the α-, β-, and γ-site with luminescence coefficients (for semiquantitative analysis) ζα = 10.1, ζβ = 9.4, and ζγ = 8.8 mmol/g of Zn2+ ions in the α-, β-, and γ-sites, respectively. The analysis of Zn ions in ferrierites showed that ZnH-ferrierites exclusively contain Zn2+ ions in cationic sites. In the case of the ZnNa-FER sample with maximum Zn loading (Zn/Al 0.33), a small amount of Zn-oxo species can be formed. Workplace J. Heyrovsky Institute of Physical Chemistry Contact Michaela Knapová, michaela.knapova@jh-inst.cas.cz, Tel.: 266 053 196 Year of Publishing 2022 Electronic address http://hdl.handle.net/11104/0319851
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