In situ Monitoring of n-Butene Conversion on H-Ferrierite by 1H, 2H, and 13C MAS NMR: Kinetics of a Double-Bond-Shift Reaction, Hydrogen Exchange, and the 13C-Label Scrambling Full article
| Journal |
Journal of Catalysis
ISSN: 0021-9517 , E-ISSN: 1090-2694 |
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| Output data | Year: 2005, Volume: 229, Number: 1, Pages: 243-251 Pages count : 9 DOI: 10.1016/j.jcat.2004.10.021 | ||||
| Tags | 13C MAS NMR spectroscopy, 13C-label scrambling, Double-bond-shift reaction, H-FER zeolite, H/D exchange, Kinetics, n-Butene, Reaction mechanism | ||||
| Authors |
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| Affiliations |
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Funding (5)
| 1 | Russian Foundation for Basic Research | 04-03-32372 |
| 2 | Siberian Branch of the Russian Academy of Sciences | |
| 3 | German Research Foundation | FR 902/15 |
| 4 | German Research Foundation | |
| 5 | Russian Science Support Foundation |
Abstract:
Kinetics of a double-bond-shift reaction, hydrogen exchange, and 13C-label scrambling were monitored in situ by 2H, 1H, and 13C MAS NMR for n-but-1-ene adsorbed on the zeolite ferrierite under batch reactor conditions at 290–373 K. A double-bond-shift reaction, the fastest among the three reactions studied, can be monitored provided that 97% of Brønsted acid sites are substituted by Na cations. The activation energy for this reaction was found to be 9.8 kcal mol−1. Hydrogen exchange with protons from the zeolite is observed for both methene and methyl groups of n-but-2-ene, formed from the initial n-but-1-ene. The terminal olefinic double bond; length as m-dashCH2 group of n-but-1-ene is involved in the exchange, providing the pathway for the exchange into the methyl group of the n-but-2-ene, mainly observed in the spectrum in accordance with thermodynamic equilibrium between n-but-1-ene and n-but-2-ene. This offers similar apparent activation energies of about 7 kcal mol−1 for the exchange into methene and methyl groups of n-but-2-ene. The 13C-label scrambling in n-but-2-ene is indicative of sec-butyl cation formation from the olefin in the zeolite framework, which can be formed as a small quantity of transient species not detectable by NMR but providing the label scrambling. The apparent activation energy for the 13C-label scrambling was found to be 21 ± 2 kcal mol−1, which is three times higher compared with the activation energy for the label scrambling in sec-butyl cation in a superacidic solution.
Cite:
Stepanov A.G.
, Arzumanov S.S.
, Luzgin M.V.
, Ernst H.
, Freude D.
In situ Monitoring of n-Butene Conversion on H-Ferrierite by 1H, 2H, and 13C MAS NMR: Kinetics of a Double-Bond-Shift Reaction, Hydrogen Exchange, and the 13C-Label Scrambling
Journal of Catalysis. 2005. V.229. N1. P.243-251. DOI: 10.1016/j.jcat.2004.10.021 WOS Scopus РИНЦ ANCAN OpenAlex
In situ Monitoring of n-Butene Conversion on H-Ferrierite by 1H, 2H, and 13C MAS NMR: Kinetics of a Double-Bond-Shift Reaction, Hydrogen Exchange, and the 13C-Label Scrambling
Journal of Catalysis. 2005. V.229. N1. P.243-251. DOI: 10.1016/j.jcat.2004.10.021 WOS Scopus РИНЦ ANCAN OpenAlex
Dates:
| Submitted: | Aug 24, 2004 |
| Accepted: | Oct 25, 2004 |
| Published online: | Dec 15, 2004 |
| Published print: | Jan 1, 2005 |
Identifiers:
| Web of science: | WOS:000226290900026 |
| Scopus: | 2-s2.0-11044227237 |
| Elibrary: | 14382635 |
| Chemical Abstracts: | 2005:3172 |
| Chemical Abstracts (print): | 142:197465 |
| OpenAlex: | W2095722778 |