Al and Ti Location in the MFI Orthorhombic HZSM-5 Framework. DFT Calculation and Neutron Diffraction Experiment | Sciact - CRIS-system of Boreskov Institute of Catalysis

Al and Ti Location in the MFI Orthorhombic HZSM-5 Framework. DFT Calculation and Neutron Diffraction Experiment Full article

Journal

Journal of Materials Science
ISSN: 0022-2461 , E-ISSN: 1573-4803

Output data

Year: 2023, Volume: 58, Pages: 3934–3946 Pages count : 13 DOI: 10.1007/s10853-023-08294-w

Tags

Aluminum; Catalyst activity; Crystal atomic structure; Ions; Neutron diffraction; Silicon; Titanium; Zeolites

Authors

Domoroshchina Elena N. ¹ , Svetogorov Roman D. ² , Kuz’micheva Galina M. ¹ , Kravchenko Galina V. ¹ , Pirutko Larisa V. ³ , Zhukova Anna I. ⁴ , Utenyshev Andrey N. ⁵ , Bozhenko Konstantin V. ^4,5

Affiliations

1	MIREA-Russian Technological University (RTU MIREA), 78 Vernadsky Avenue, Moscow, Russia, 119454
2	National Research Center “Kurchatov Institute”, 1, Akademika Kurchatova Pl, Moscow, Russia, 123182
3	Boreskov Institute of Catalysis, Siberian Branch, 5, Lavrentiev Ave, Novosibirsk, Russia, 630090
4	Friendship University of Russia (RUDN University), 6, Miklukho-Maklaya Str, Moscow, Russia, 117198
5	Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov av, Chernogolovka, Russia, 142432

Funding (2)

1	Ministry of Science and Higher Education of the Russian Federation	0706-2020-0026
2	Ministry of Science and Higher Education of the Russian Federation	0089-2019-0013 (АААА-А19-119092390076-7)

For the first time the neutron diffraction study of HZSM-5 zeolites with the general composition of (H1+x)[Al3+xSi4+12-xO24] × wH2O in the orthorhombic approximation (sp. gr. Pnma, z = 8) and initial silicate modules Si/Al = 12, 25, 40 was carried out. As a result, the composition was refined, the distribution of Al3+ ions over the tetrahedral sites (T sites) of the structure was found, and their content in each of them was estimated. It was found that T sites occupation in HZSM-5 structure differ depending on Si/Al, while samples with the same silicate module (Si/Al = 40) obtained under different synthesis conditions differ in the distribution of Al3+ ions over T sites of the structure. It was shown that the calculation of HZSM-5 zeolites crystal structure with substitutions in T sites performed using the VASP 5.2 program with different optimizations (atomic coordinates and unit cell parameters) can only reveal the most thermodynamically energetically favorable sites for Si4+ atoms substitution with other atoms (aluminum and titanium) without predicting their content in each site and regardless zeolite synthesis conditions and type of substituent atom. The relationship between HZSM-5 zeolites catalytic properties and silicate module (Si/Al, Si/Ti) was found and it cannot be ruled out that HZSM-5 catalytic activity is related to Ti4+ ions distribution over the tetrahedral sites of the structure.

Domoroshchina E.N. , Svetogorov R.D. , Kuz’micheva G.M. , Kravchenko G.V. , Pirutko L.V. , Zhukova A.I. , Utenyshev A.N. , Bozhenko K.V.
Al and Ti Location in the MFI Orthorhombic HZSM-5 Framework. DFT Calculation and Neutron Diffraction Experiment
Journal of Materials Science. 2023. V.58. P.3934–3946. DOI: 10.1007/s10853-023-08294-w WOS Scopus РИНЦ ANCAN OpenAlex

Submitted:	Sep 7, 2022
Accepted:	Feb 7, 2023
Published online:	Feb 21, 2023
Published print:	Mar 1, 2023

Web of science:	WOS:000936228900004
Scopus:	2-s2.0-85148431578
Elibrary:	54798408
Chemical Abstracts:	2023:365602
Chemical Abstracts (print):	182:122939
OpenAlex:	W4321437741

DB	Citing
Scopus	2
Web of science	4
OpenAlex	5
Elibrary	4