Propane Activation on Zn-Modified Zeolite. The Effect of the Nature of Zn-Species on the Mechanism of H/D Hydrogen Exchange of the Alkane with Brønsted Acid Sites
Научная публикация
| Общее |
Язык:
Английский,
Жанр:
Статья (Full article),
Статус опубликования:
Опубликована,
Оригинальность:
Оригинальная
|
| Журнал |
Journal of Catalysis
ISSN: 0021-9517
, E-ISSN: 1090-2694
|
| Вых. Данные |
Год: 2019,
Том: 378,
Страницы: 341-352
Страниц
: 12
DOI:
10.1016/j.jcat.2019.09.006
|
| Ключевые слова |
1H MAS NMR in situ; Activation; Brønsted acid sites; H/D hydrogen exchange; Mechanism; Nature of Zn species; Propane; Zn-modified H-BEA zeolite; Zn2+ cations; ZnO small clusters |
| 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, Russian Federation
|
| 2 |
Novosibirsk State University, Faculty of Natural Sciences, Department of Physical Chemistry, Pirogova Str. 2, Novosibirsk, 630090, Russian Federation
|
| 3 |
Universität Leipzig, Fakultät für Physik und Geowissenschaften, Linnéstr. 5, Leipzig, 04103, Germany
|
|
Информация о финансировании (2)
|
1
|
Российский научный фонд
German Research Foundation
|
19-43-04101
|
|
2
|
German Research Foundation
|
HA 1893/22-1
|
Zn-modified zeolites exhibit high activity for the aromatization of C2+ alkanes. To understand the effect of Zn-species of different nature on propane molecules activation and transformation, the H/D hydrogen exchange of zeolite Brønsted acid sites (BAS) with deuterated propane-d8 has been investigated. Two samples of the Zn-modified zeolite containing exclusively either isolated Zn2+ cations (Zn2+/H-BEA) or small (ZnO)n clusters (ZnO/H-BEA) have been studied. Zn-species of either type work jointly with BAS and may provide the synergy effect for propane C[sbnd]H bond activation resulting in dramatic acceleration of the H/D exchange between propane and BAS. The accelerating effect of isolated Zn2+ cations is more pronounced compared to zinc oxide clusters. Moreover, the H/D exchange occurs regioselectively into the methyl groups of propane on Zn2+/H-BEA zeolite. For ZnO/H-BEA, the methylene group becomes also involved in the exchange after some induction period. Various mechanisms providing the regioselective H/D exchange on Zn2+/H-BEA as well as the involvement of the methylene group after the induction period on ZnO/H-BEA are discussed. © 2019 Elsevier Inc.