Mechanism of H/D Hydrogen Exchange of n-Butane with Brønsted Acid Sites on Zn-Modified Zeolite: The Effect of Different Zn Species (Zn2+ and ZnO) on the Activation of Alkane C–H Bonds | Sciact - CRIS-система Института катализа

Mechanism of H/D Hydrogen Exchange of n-Butane with Brønsted Acid Sites on Zn-Modified Zeolite: The Effect of Different Zn Species (Zn2+ and ZnO) on the Activation of Alkane C–H Bonds Научная публикация

Журнал

The Journal of Physical Chemistry C
ISSN: 1932-7447 , E-ISSN: 1932-7455

Вых. Данные

Год: 2020, Том: 124, Номер: 37, Страницы: 20270-20279 Страниц : 10 DOI: 10.1021/acs.jpcc.0c06616

Ключевые слова

C-13 MAS NMR, High-silica zeolites, Light alkanes, Propane aromatization, Zn/MFI catalyst, ZSM-5 zeolites, Active sites, Conversion, H-1, Ethane

Авторы

Arzumanov Sergei S. ^1,2 , Gabrienko Anton A. ^1,2 , Toktarev Alexander V. ¹ , Freude Dieter ³ , Haase Jürgen ³ , Stepanov Alexander G. ^1,2

Организации

1	Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Prospekt Akademika Lavrentieva 5, Novosibirsk 630090, Russia
2	Faculty of Natural Sciences, Department of Physical Chemistry, Novosibirsk State University, Pirogova Street 2, Novosibirsk 630090, Russia
3	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

With the aim of clarifying the effect of Zn species of different nature (small clusters of ZnO and Zn2+ cations) on the activation of alkane C–H bonds by Zn-modified zeolite, the mechanism of the H/D hydrogen exchange of n-butane-d10 with Brønsted acid sites (BASs) of ZnO/H-BEA and Zn2+/H-BEA zeolites has been investigated with 1H MAS NMR in situ at 413–468 K. It is established that both ZnO and Zn2+ species provide acceleration of the exchange in the methyl groups with a decreased activation energy compared to the exchange in n-butane on pure acid-form zeolite. The effect of Zn2+ cation is more essential. The acceleration has been attributed to the formation of transient complexes of the alkane methyl groups with Zn species preceding the exchange with BAS. For ZnO/H-BEA, the involvement of the methylene groups in the exchange is related to the alkane dehydrogenation to form butene followed by protonation and hydride shift reaction in the formed butyl cation. For Zn2+/H-BEA zeolite, an enhanced rate of the exchange in the methylene groups is due to the contribution of two pathways: direct exchange with the assistance of Zn2+ cations and through the intermediate formation of n-butene. We have concluded that the observed peculiarities of the kinetics of H/D hydrogen exchange of n-butane on Zn2+/H-BEA and ZnO/H-BEA zeolites could be rationalized in terms of a common kinetic scheme realized for two zeolite samples with different kinetic parameters, rate constants, and activation energies for identical reaction steps.

Arzumanov S.S. , Gabrienko A.A. , Toktarev A.V. , Freude D. , Haase J. , Stepanov A.G.
Mechanism of H/D Hydrogen Exchange of n-Butane with Brønsted Acid Sites on Zn-Modified Zeolite: The Effect of Different Zn Species (Zn2+ and ZnO) on the Activation of Alkane C–H Bonds
The Journal of Physical Chemistry C. 2020. V.124. N37. P.20270-20279. DOI: 10.1021/acs.jpcc.0c06616 WOS Scopus РИНЦ CAPlus OpenAlex

Поступила в редакцию:	20 июл. 2020 г.
Принята к публикации:	19 авг. 2020 г.
Опубликована online:	19 авг. 2020 г.
Опубликована в печати:	17 сент. 2020 г.

Web of science:	WOS:000574908200041
Scopus:	2-s2.0-85095445222
РИНЦ:	45193895
Chemical Abstracts:	2020:1629279
OpenAlex:	W3071892815

БД	Цитирований
Web of science	15
Scopus	15
РИНЦ	13
OpenAlex	15