The effect of rhenium, sulfur and alumina on the conversion of hydrocarbons over platinum single crystals: Surface science and catalytic studies
Conversion reactions of hydrocarbons over the platinum-rhenium model catalyst surfaces have been studied. The Pt-Re bimetallic surfaces were prepared by depositing Re onto Pt(111) or Pt onto Re(0001) in ultrahigh vacuum. These model catalyst surfaces were modified by sulfur and alumina and the effects of these modification on the conversion of hydrocarbons were also studied. A plasma deposition source has been developed to deposit platinum, rhenium, and aluminum on the metal substrates. The deposition source has proven to be very effective for the deposition of refractory metals with variable coverage in ultrahigh vacuum without excessive heating. Conversion of n-hexane was performed over the Re-covered Pt and Pt-Covered Re surfaces. The presence of the second metal increased hydrogenolysis activity of both Pt-Re surfaces. Addition of sulfur on the model catalyst surfaces suppressed hydrogenolysis activity and increased the cyclization rate of n-hexane to methylcyclopentane over Pt-Re surfaces. It was also observed that sulfiding increased the dehydrogenation rate of cyclohexane to benzene over Pt-Re surfaces. It has been proposed that the Pt-Re bimetallic catalysts show unique properties when combined with sulfur, and electronic interactions exist between platinum, rhenium and sulfur. Decomposition of hydrocarbons on the sulfur-covered Pt-Re surfaces supported that argument. The planar Pt/AlO[sub x] catalyst was prepared by oxidizing the surface of aluminum foil followed by deposition of atomic platinum onto the aluminum oxide surface. For the conversion of 1-butene over this catalyst, the addition of platinum increased the selectivity of hydrogenation over isomerization.
- Research Organization:
- California Univ., Berkeley, CA (United States)
- OSTI ID:
- 5652311
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ALUMINIUM OXIDES
CATALYTIC EFFECTS
CATALYST SUPPORTS
SURFACE PROPERTIES
HYDROCARBONS
CHEMICAL REACTIONS
RHENIUM
SULFUR
MONOCRYSTALS
PHYSICAL VAPOR DEPOSITION
PLATINUM
ALUMINIUM COMPOUNDS
CHALCOGENIDES
CRYSTALS
DEPOSITION
ELEMENTS
METALS
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
SURFACE COATING
TRANSITION ELEMENTS
400201* - Chemical & Physicochemical Properties