Skeletal isomerization of hydrocarbons on molybdenum catalysts II. Catalytic study of unsupported catalysts: Film and powder
1987; Elsevier BV; Volume: 104; Issue: 1 Linguagem: Inglês
10.1016/0021-9517(87)90350-2
ISSN1090-2694
AutoresY. Holl, F. Garin, G. Maire, Anke-Susanne Müller, P.A. Engelhard, J. Grosmangin,
Tópico(s)Catalysis and Oxidation Reactions
ResumoMechanisms of skeletal isomerization of hydrocarbons were studied on unsupported molybdenum catalysts, both powder and film, by 13C labeling techniques and gas-phase chromatography. Catalytic results are very different on film and on powder. On film very fast extensive cracking was obtained, whereas on powder isomerization largely predominated. The most likely interpretation of the catalytic results on molybdenum powder is that isomerization occurs on metallic sites. The cyclic mechanism which has been observed on platinum, palladium, and indium is not observed on molybdenum. All isomerization proceeds by the bond shift mechanism through αγ-diadsorbed species of metallacyclobutane-type structure. This mechanism is close to that of olefin metathesis. Complete isomerization diagrams are proposed for several labeled hydrocarbons.
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