Does the Zn2+ Species Introduced into H-ZSM-5 Zeolite Affect the Strength of Brønsted Acid Sites? Full article
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ChemCatChem
ISSN: 1867-3880 , E-ISSN: 1867-3899 |
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| Output data | Year: 2020, Volume: 12, Number: 2, Pages: 478-487 Pages count : 10 DOI: 10.1002/cctc.201901637 | ||||||
| Tags | Brønsted acid sites; FTIR spectroscopy; solid-state NMR; zeolite; zinc | ||||||
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| Affiliations |
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Funding (2)
| 1 | Russian Foundation for Basic Research | 18-03-00189 |
| 2 | Federal Agency for Scientific Organizations | 0303-2016-0003 |
Abstract:
To clarify the issue on Brønsted acidity enhancement by the presence of zinc species in H-ZSM-5 zeolite (G.D. Qi, et al., Angew. Chem.-Int. Edit. 2016 , 55 , 15826), the influence of Zn2+ cationic species, introduced into the zeolite, on the strength of Brønsted acid sites (BAS) has been analyzed by solid-state NMR and FTIR techniques using trimethylphosphine (TMP) and CO as probe molecules. Comparative analysis of the acidity for H-ZSM-5 and Zn2+/H-ZSM-5 zeolites has been performed. TMP adsorbed on both zeolite samples exhibits same signals at 6.3 and –4.5 ppm in 1 H and 31 P MAS NMR spectra, respectively, assigned to protonated TMP. FTIR spectroscopy has shown that both zeolite samples, H-ZSM-5 and Zn 2+ /H-ZSM-5, display the same red frequency shift (Δν OH…CO = –318 cm –1 ) of the O–H stretching band and the same blue frequency shift (Δν CO = +32 cm –1 ) of the CO stretching band for CO adsorption complex with BAS. The results obtained do not provide any evidence for the existence of some specific BAS with enhanced acid strength for Zn2+ -exchanged zeolite compared to the strength inherent to pure acid form zeolite. It is thus inferred the strength of BAS in H-ZSM-5 zeolite is not affected by the modification of the zeolite with Zn2+ cationic species.
Cite:
Gabrienko A.A.
, Danilova I.G.
, Arzumanov S.S.
, Freude D.
, Stepanov A.G.
Does the Zn2+ Species Introduced into H-ZSM-5 Zeolite Affect the Strength of Brønsted Acid Sites?
ChemCatChem. 2020. V.12. N2. P.478-487. DOI: 10.1002/cctc.201901637 WOS Scopus РИНЦ OpenAlex ANCAN
Does the Zn2+ Species Introduced into H-ZSM-5 Zeolite Affect the Strength of Brønsted Acid Sites?
ChemCatChem. 2020. V.12. N2. P.478-487. DOI: 10.1002/cctc.201901637 WOS Scopus РИНЦ OpenAlex ANCAN
Dates:
| Submitted: | Aug 30, 2019 |
| Accepted: | Sep 23, 2019 |
| Published online: | Oct 31, 2019 |
| Published print: | Jan 18, 2020 |
Identifiers:
| ≡ Web of science: | WOS:000508685300010 |
| ≡ Scopus: | 2-s2.0-85074781925 |
| ≡ Elibrary: | 43211091 |
| ≡ OpenAlex: | W2976793929 |
| ≡ Chemical Abstracts: | 2019:2068614 |
| ≡ Chemical Abstracts (print): | 172:134020 |