Hydrocarbon reactions on supported iridium catalysts. [2,2-dimethylbutane, 2,3-dimethylbutane, methylcylopentane]
In a study related to the development of platinum-iridium reforming catalysts, the reactions of ethane, n-butane, isobutane, neopentane, 2,2-dimethylbutane, 2,3-dimethylbutane, and methylcyclopentane with hydrogen were studied on six silica- or alumina-supported iridium catalysts prepared by different methods and containing different iridium crystallite sizes. Two types of reactions were observed: the ''C/sub 2/-unit mode'', which included the rupture of primary-primary, primary-secondary, and secondary-secondary carbon bonds, e.g., of ethane, had an activation energy of approx. 175 kj/mole, and had a frequency factor of approx. 10/sup 17/ molecules/sec per iridium site which was independent of crystallite size; and the ''iso-unit mode'', which included the rupture of primary-quaternary, primary-tertiary, and secondary-tertiary carbon bonds, had an activation energy of approx. 235 kj/mole, and had a frequency factor of approx. 10/sup 21/ molecules/sec per iridium site which was independent of crystallite size. Some isomerization of isopentane and n-butane was observed. The reaction mechanisms were discussed and compared with alkane hydrogenolysis mechanisms on platinum.
- Research Organization:
- Univ. of Melbourne
- OSTI ID:
- 6197818
- Journal Information:
- J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 59:3; ISSN JCTLA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
2-METHYLPROPANE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ACTIVATION ENERGY
ALKANES
BUTANE
CATALYSTS
CATALYTIC EFFECTS
CHEMICAL BONDS
CHEMICAL COMPOSITION
CHEMICAL PREPARATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COMPARATIVE EVALUATIONS
CRYSTAL STRUCTURE
DATA
ELEMENTS
ENERGY
ETHANE
EXPERIMENTAL DATA
HYDROCARBONS
HYDROGEN
INFORMATION
IRIDIUM
KINETICS
METALS
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
PLATINUM
PLATINUM METALS
REACTION KINETICS
SYNTHESIS
TRANSITION ELEMENTS