Tracer studies of cyclopropane reactions on molybdena-alumina catalysts

Journal Article · Wed Feb 01 04:00:00 EST 1978 · J. Catal.; (United States)

DOI:https://doi.org/10.1016/0021-9517(78)90298-1· OSTI ID:5164710

Lombardo, E A; Lo Jacono, M; Hall, W K

The oxidation state of a molybdena-..gamma..-Al/sub 2/O/sub 3/ (8%) catalyst was varied by reduction with either H/sub 2/ or CO under carefully controlled conditions. The decomposition of cyclopropane was studied and correlations were sought between surface chemistry and catalytic function. Temperatures between 50 and 130/sup 0/C and a pulse reactor were employed. In every case propylene, ethylene, and n-butenes were produced in proportions depending upon the extent of reduction. When cyclopropane was reacted over a catalyst reduced with D/sub 2/, deuterated propylenes were formed in increasing percentages with higher extents of reduction. Similar results were obtained when the catalyst was first thoroughly reduced with D/sub 2/, then reoxidized and finally reduced to different extents with CO. When mixtures of cyclopropane-d/sub 0/ and -d/sub 6/ were co-isomerized, the products were readily equilibrated. Methylcylopropane reacted much faster than cyclopropane, yielding both isomerization and metathesis products. No trace of isobutane was detected. A small portion of the first cyclopropane to contact the catalyst reacted to form ethylene and the methylene carbene. Otherwise the data were consistent with a proton-catalyzed ring opening followed by metathesis on coordinatively unsaturated Mo (IV) ions occurring through a carbene mechanism. The results are discussed in terms of current literature..

• Research Organization: Univ. of Wisconsin, Milwaukee
• OSTI ID: 5164710
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 51:2; ISSN JCTLA
• Country of Publication: United States
• Language: English

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ALKANES
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CRYOGENIC FLUIDS
CYCLOALKANES
DECOMPOSITION
DEUTERIUM
ELEMENTS
FLUIDS
HYDROCARBONS
HYDROGEN
HYDROGEN ISOTOPES
ISOTOPE EFFECTS
ISOTOPES
LIGHT NUCLEI
MOLYBDENUM COMPOUNDS
MOLYBDENUM OXIDES
NONMETALS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PROPANE
REDUCTION
STABLE ISOTOPES
TRANSITION ELEMENT COMPOUNDS