Selective isomerization of n-hexane over nickel on silica-alumina catalysts
Comparative tests on the isomerization of n-hexane were conducted with reduced (H/sub 2/, 770/sup 0/K) 5-16Vertical Bar3< Ni on silica/alumina, Ni powder, 2.9Vertical Bar3< Ni on silica, 7Vertical Bar3< Ni on alumina, and commercial molybdenum, platinum, and palladium reforming catalysts. In flow reactor tests, the activity (n-hexane conversion) and selectivity for isomerization of the 7Vertical Bar3< Ni on silica/alumina catalyst were similar to those of the platinum catalyst. In pulse reactor tests, the activity and selectivity of this 7Vertical Bar3< Ni catalyst were 5 and 98.2Vertical Bar3<, respectively, at 603/sup 0/K, 7.5 and 95.3Vertical Bar3<, respectively, at 633/sup 0/K, and 11.1 and 83.1Vertical Bar3< at 663/sup 0/K; the decrease in hexane isomerization activity with increasing temperature corresponded to an increase in propane yield and only to a small increase in methane production. Hydrogen reduction indicated that the nickel of this catalyst was present as nickel(0), but neither X-ray nor magnetic measurements indicated the presence of metallic nickel. These and other data suggested that the isomerization proceeds on a zero-valent nickel/aluminum atom site, which is inactive in hydrogenolysis. A mechanism is proposed.
- Research Organization:
- Univ. of Reading, Reading (United Kingdom)
- OSTI ID:
- 6950291
- Journal Information:
- J. Catal.; (United States), Vol. 58:2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CATALYSTS
CHEMICAL REACTIONS
HEXANE
ISOMERIZATION
NICKEL
CATALYTIC EFFECTS
ALUMINIUM OXIDES
BENCH-SCALE EXPERIMENTS
EXPERIMENTAL DATA
SILICA
ALKANES
ALUMINIUM COMPOUNDS
CHALCOGENIDES
DATA
ELEMENTS
HYDROCARBONS
INFORMATION
METALS
MINERALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
SILICON COMPOUNDS
SILICON OXIDES
TRANSITION ELEMENTS
400300* - Organic Chemistry- (-1987)
400201 - Chemical & Physicochemical Properties