Isobutane Transformation to Aromatics on Zn‐Modified Zeolites. The Intermediates and the Effect of Zn2+ and ZnO Species on the Reaction Occurrence Revealed with 13C MAS NMR | Sciact - CRIS-система Института катализа

Isobutane Transformation to Aromatics on Zn‐Modified Zeolites. The Intermediates and the Effect of Zn2+ and ZnO Species on the Reaction Occurrence Revealed with 13C MAS NMR Научная публикация

Журнал

ChemPhysChem
ISSN: 1439-4235 , E-ISSN: 1439-7641

Вых. Данные

Год: 2022, Том: 23, Номер: 1, Номер статьи : e2021005, Страниц : 9 DOI: 10.1002/cphc.202100587

Ключевые слова

13C MAS NMR; Zn-modified zeolite; 13C-labelled isobutane; mechanism; aromatization

Авторы

Gabrienko Anton A. ¹ , Lashchinskaya Zoya N. ¹ , Arzumanov Sergei S. ¹ , Toktarev Alexander V. ¹ , Freude Dieter ² , Haase Jürgen ² , Stepanov Alexander G. ¹

Организации

1	Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Prospekt Akademika Lavrentieva 5, Novosibirsk 630090, Russia
2	Fakultät für Physik und Geowissenschaften, Universität Leipzig. Linnéstr. 5, 04103 Leipzig, Germany

Информация о финансировании (2)

1	Российский научный фонд German Research Foundation	19-43-04101
2	German Research Foundation	HA 1893/22-1

To clarify the effects of different Zn species, zeolite topology and acidity (quantity of Brønsted acid sites, BAS) on alkane aromatization, isobutane transformation on Zn 2+ /H-ZSM-5, Zn 2+ /H-BEA, and ZnO/H-BEA zeolites has been monitored with 13 C MAS NMR. The alkane transformation has been established to occur by aromatization and hydrogenolysis pathways. Zn 2+ species is more efficient for the aromatization reaction because aromatic products are formed at lower temperatures on Zn 2+ /H-BEA and Zn 2+ /H-ZSM-5 than on ZnO/H-BEA. The larger quantity of BAS in ZnO/H-BEA seems to provide a higher degree of the hydrogenolysis pathway on this catalyst. The mechanism of the alkane aromatization is similar for the zeolites of different topology and containing different Zn species, with the main reaction steps being the following: (i) isobutane dehydrogenation to isobutene via isobutylzinc; (ii) isobutene stabilization as a π-complex on Zn sites; (iii) isobutene oligomerization via the alkene insertion into Zn–C bond of methyl-σ-allylzinc formed from the π-complex; (iv) oligomer dehydrogenation with intermediate formation of polyene carbanionic structures; (v) aromatics formation via further polyene dehydrogenation, protonation, cyclization, deprotonation steps with BAS involvement.

Gabrienko A.A. , Lashchinskaya Z.N. , Arzumanov S.S. , Toktarev A.V. , Freude D. , Haase J. , Stepanov A.G.
Isobutane Transformation to Aromatics on Zn‐Modified Zeolites. The Intermediates and the Effect of Zn2+ and ZnO Species on the Reaction Occurrence Revealed with 13C MAS NMR
ChemPhysChem. 2022. V.23. N1. e2021005 :1-9. DOI: 10.1002/cphc.202100587 WOS Scopus РИНЦ CAPlusCA PMID OpenAlex

Поступила в редакцию:	4 авг. 2021 г.
Принята к публикации:	6 сент. 2021 г.
Опубликована online:	9 сент. 2021 г.
Опубликована в печати:	5 янв. 2022 г.

Web of science:	WOS:000700134400001
Scopus:	2-s2.0-85115690254
РИНЦ:	47104952
Chemical Abstracts:	2021:2125417
Chemical Abstracts (print):	178:97063
PMID (PubMed):	34505329
OpenAlex:	W3197806230

БД	Цитирований
Web of science	4
Scopus	6
РИНЦ	5
OpenAlex	6