N-Butane Conversion on Sulfated Zirconia: In situ 13C MAS NMR Monitoring of the Kinetics of the 13C-Label Scrambling and Isomerization Full article
Journal |
Catalysis Letters
ISSN: 1011-372X , E-ISSN: 1572-879X |
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Output data | Year: 2005, Volume: 101, Number: 3-4, Pages: 181-185 Pages count : 5 DOI: 10.1007/s10562-005-4887-1 | ||||||
Tags | 13C MAS NMR, Hydrogen exchange, N-butane conversion, Sulfated zirconia | ||||||
Authors |
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Affiliations |
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Funding (5)
1 | German Research Foundation | FR 902/15 |
2 | Russian Foundation for Basic Research | 04-03-32372 |
3 | Siberian Branch of the Russian Academy of Sciences | |
4 | North Atlantic Treaty Organization | PST.CLG.979335 |
5 | Russian Science Support Foundation |
Abstract:
The kinetics of the conversion of 13C-labeled n-butane adsorbed on sulfated zirconia (SZ) were monitored by in situ 13C MAS NMR spectroscopy. Rate constants of n- to isobutane isomerization and of the 13C-isotope scrambling from the primary to the secondary carbon atoms in n-butane were determined. The monomolecular scrambling of the
13C-label in adsorbed n-butane has an activation energy of 17 ± 3 kcal mol−1 and occurs faster than the bimolecular process of n-butane isomerization which has an activation energy of 15.1 ± 0.2 kcal mol−1. The transfer of the selective 13C-label from the primary to the secondary carbon atom in the adsorbed n-butane seems to consist of two reaction steps: (i) a hydride abstraction by SZ leading to the formation of sec-butyl cations and (ii) a label scrambling in the sec-butyl cations. This two-step process with the formation of sec-butyl cations as intermediate increases the apparent activation energy for the 13C-label scrambling, which is almost twice as large compared with the activation energy for carbon scrambling of sec-butyl cations in a superacidic solution.
Cite:
Stepanov A.G.
, Luzgin M.V.
, Arzumanov S.S.
, Wang W.
, Hunger M.
, Freude D.
N-Butane Conversion on Sulfated Zirconia: In situ 13C MAS NMR Monitoring of the Kinetics of the 13C-Label Scrambling and Isomerization
Catalysis Letters. 2005. V.101. N3-4. P.181-185. DOI: 10.1007/s10562-005-4887-1 WOS Scopus РИНЦ
N-Butane Conversion on Sulfated Zirconia: In situ 13C MAS NMR Monitoring of the Kinetics of the 13C-Label Scrambling and Isomerization
Catalysis Letters. 2005. V.101. N3-4. P.181-185. DOI: 10.1007/s10562-005-4887-1 WOS Scopus РИНЦ
Dates:
Submitted: | Mar 23, 2004 |
Accepted: | Jan 11, 2005 |
Published print: | Jun 1, 2005 |
Identifiers:
Web of science | WOS:000229511400009 |
Scopus | 2-s2.0-21044449314 |
Elibrary | 13487461 |
Chemical Abstracts | 2005:463684 |
Chemical Abstracts (print) | 143:132957 |
OpenAlex | W2034722513 |