Document Detail


(1)H and (13)C MAS NMR studies of light alkanes activation over MFI zeolite modified by Zn vapour.
MedLine Citation:
PMID:  19286356     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The early stages of methane, ethane and propane conversion were studied by in situ (1)H and (13)C MAS NMR techniques over fully exchanged Zn(2+)/MFI catalyst obtained by the reaction with zinc vapour. The in situ techniques revealed strong interaction of alkanes with Zn(2+) cations evidenced by significant shift of the corresponding NMR lines. Besides that, the formation of methyl zinc, ethyl zinc and n-propyl zinc species along with bridging and silanol surface OH-groups was detected already at the ambient temperature. These results pointed to dissociative adsorption of alkanes over (ZO)-Zn(2+)-(OZ) and (ZO)-Zn(2+)-(OSi) active sites of the catalyst. The dissociative adsorption was shown to be a dead-end surface reaction in the case of methane starting reactant, while in the case of ethane and propane, it appeared to be responsible for the initiation of the catalytic cycle leading to alkenes and dihydrogen formation and regeneration of zinc containing catalytic sites.
Authors:
Yuriy G Kolyagin; Irina I Ivanova; Yuri A Pirogov
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-02-12
Journal Detail:
Title:  Solid state nuclear magnetic resonance     Volume:  35     ISSN:  0926-2040     ISO Abbreviation:  Solid State Nucl Magn Reson     Publication Date:  2009 Apr 
Date Detail:
Created Date:  2009-04-07     Completed Date:  2009-07-07     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9306181     Medline TA:  Solid State Nucl Magn Reson     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  104-12     Citation Subset:  IM    
Affiliation:
Department of Chemistry, Moscow State University, Lenin Hills 1/3, 119991 Moscow, Russia.
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MeSH Terms
Descriptor/Qualifier:
Alkanes / chemistry*
Carbon Isotopes / analysis,  chemistry*
Catalysis
Computer Simulation
Gases / chemistry
Magnetic Resonance Spectroscopy / methods*
Models, Chemical*
Models, Molecular*
Molecular Conformation
Protons
Zeolites / analysis,  chemistry*
Zinc / chemistry*
Chemical
Reg. No./Substance:
0/Alkanes; 0/Carbon Isotopes; 0/Gases; 0/Protons; 1318-02-1/Zeolites; 7440-66-6/Zinc

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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