catalytic alkane metathesis by tandem alkane dehydrogenation– olefin metathesis
DESCRIPTION
Catalytic Alkane Metathesis by Tandem Alkane Dehydrogenation– Olefin Metathesis. Fischer-Tropsch. http://en.wikipedia.org/wiki/Fischer-Tropsch_synthesis. Alkane Metathesis. Tandem Alkane Dehydrogenation– Olefin Metathesis. Molecular Redistribution Mechanism by Olefin Intermediates. 24.7%. - PowerPoint PPT PresentationTRANSCRIPT
Catalytic Alkane Metathesis byTandem Alkane Dehydrogenation–
Olefin Metathesis
Fischer-Tropsch
CH4 + 1/2O2 2H2 + CO
(2n+1)H2 + nCO CnH2n+2 + nH2O
http://en.wikipedia.org/wiki/Fischer-Tropsch_synthesis
Alkane Metathesis
Tandem Alkane Dehydrogenation–Olefin Metathesis
n(Cn) C(2n-2) + ethane
Molecular Redistribution Mechanism by Olefin Intermediates
24.7% 15.9%
Burnett, R. L., Hughes, T. R. J. Catal. 1973, 31, 55
Dehydrogenation catalysts
Schrock-type Metathesis Catalyst
Schrock, R. R. et. al. J. Am. Chem. Soc. 1990, 112, 3875
Representative Examples of the Metathesis of n-hexane
TBEbutylethylene
The Mechanism of Metathesis and Dehydrogenation
Goldman, A. S. et. al. J. Am. Chem. Soc. 1999, 121, 4087
The Reason of Decomposition
2-methyl-2-phenylpropylidene
CH:
2-methyl-2-phenylbutane
2,6-diisopropylaniline
NH2
The Metathesis by Ir-based Catalysts and Re2O7/Al2O3
Conclusions
• The decomposition of the olefin metathesis
catalysts appears to limit conversions.
• The author also expect that more active
dehydrogenation catalysts will give more turnovers before decomposition of the metathesis catalyst.