Quantitative 67Zn, 27Al and 1H MAS NMR Spectroscopy for the Characterization of Zn Species in ZSM-5 Catalysts | Sciact - CRIS-system of Boreskov Institute of Catalysis

Quantitative 67Zn, 27Al and 1H MAS NMR Spectroscopy for the Characterization of Zn Species in ZSM-5 Catalysts Full article

Journal

PCCP: Physical Chemistry Chemical Physics
ISSN: 1463-9076 , E-ISSN: 1463-9084

Output data

Year: 2023, Volume: 25, Number: 41, Pages: 28043-28051 Pages count : 9 DOI: 10.1039/d3cp03136e

Authors

Avramovska Marija ¹ , Freude Dieter ¹ , Haase Jürgen ¹ , Toktarev Alexander V. ² , Arzumanov Sergei S. ² , Gabrienko Anton A. ² , Stepanov Alexander G. ²

Affiliations

1	Faculty of Physics and Earth Sciences, Leipzig University, Linnéstraße 5, 04103 Leipzig, Germany
2	Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Prospekt Akademika Lavrentieva 5, Novosibirsk 630090, Russia

Funding (2)

1	German Research Foundation	HA 1893/22-1
2	Ministry of Science and Higher Education of the Russian Federation	0239-2021-0003

67 Zn MAS NMR spectroscopy was used to characterize the state of Zn in Zn-modified zeolites ZSM-5. Two 67Zn enriched zeolite samples were prepared: by solid-state exchange with metal 67Zn (Zn2+/ZSM-5 sample) and by ion exchange with zinc formate solution (ZnO/H-ZSM-5 sample), both containing ca. 3.8 wt% Zn. The elemental analysis, TEM, and quantitative BAS and aluminum analyses with 1H and 27Al MAS NMR have shown that Zn2+/ZSM-5 contains zinc in the form of Zn2+ cations, while both ZnO species and Zn2+ cations are present in ZnO/H-ZSM-5 besides BAS. 67Zn MAS NMR has detected the signal of Zn in a tetrahedral environment from ZnO species for both the activated and hydrated ZnO/H-ZSM-5 zeolite. The signal of Zn in an octahedral environment was detected for the hydrated Zn2+/ZSM-5 and ZnO/H-ZSM-5 zeolites. This signal may belong to zinc cation [HOZn]+ or Zn(OH)2 species surrounded by water molecules. Quantitative 67Zn MAS NMR analysis has shown that only 27 and 38% of zinc loaded in the zeolite is visible for the activated and hydrated ZnO/H-ZSM-5 zeolite, and 24% of Zn is visible for the hydrated Zn2+/ZSM-5. Zinc in the form of ZnO species is entirely visible in both the activated and hydrated ZnO/H-ZSM-5 zeolite, while Zn2+ cations are not detected at all for the activated sample and only 29% of Zn2+ cations is visible for the hydrated zeolite. Detection of only a part of Zn2+ cations in the form of [HOZn]+ or Zn(OH)2 species in octahedral environment presumes only partial hydrolysis of the bond of Zn2+ cation with framework oxygen and further solvation of the Zn species formed at hydrolysis by the adsorbed water.

Avramovska M. , Freude D. , Haase J. , Toktarev A.V. , Arzumanov S.S. , Gabrienko A.A. , Stepanov A.G.
Quantitative 67Zn, 27Al and 1H MAS NMR Spectroscopy for the Characterization of Zn Species in ZSM-5 Catalysts
PCCP: Physical Chemistry Chemical Physics. 2023. V.25. N41. P.28043-28051. DOI: 10.1039/d3cp03136e WOS Scopus РИНЦ AN PMID OpenAlex

Submitted:	Jul 4, 2023
Accepted:	Oct 10, 2023
Published online:	Oct 10, 2023
Published print:	Nov 7, 2023

Web of science:	WOS:001086988500001
Scopus:	2-s2.0-85175231729
Elibrary:	55291292
Chemical Abstracts:	2023:2137801
PMID:	37847194
OpenAlex:	W4387479113

DB	Citing
OpenAlex	4
Scopus	4
Web of science	5
Elibrary	4