Electron microscopy of supported metal particles--2. Further studies of Pt/TiO/sub 2/

Journal Article · Sat Sep 01 04:00:00 EDT 1979 · J. Catal.; (United States)

OSTI ID:6320518

Baker, R T.K.; Prestridge, E B; Garten, R L

Adsorption studies and transmission electron microscopy of 2Vertical Bar3< platinum on titanium oxide film or powder correlated the SMSI state (strong metal-support interaction) with adsorption properties. Reduction of the catalysts, followed by evacuation at 425/sup 0/K, provided highly dispersed platinum with normal adsorption behavior for hydrogen and carbon monoxide. Reduction at 875/sup 0/K suppressed the adsorption and formed hexagonal thin ''pillbox'' platinum structures in the SMSI state on reduced titanium oxide (Ti/sub 4/O/sub 7/). The reduction of the titanium oxide was catalyzed by the platinum. The platinum-titanium bond at vacancies created by oxygen removal by atomic hydrogen during reduction at 875/sup 0/K was stronger than platinum-platinum bonds. Treatment in oxygen or water vapor at 525/sup 0/ or 875/sup 0/K reoxidized the titanium surface, caused an increase of the thickness of the hexagonal platinum pillboxes, and partly restored normal adsorption behavior. On re-reducing this catalyst in hydrogen at 875/sup 0/K, a redispersion of platinum to SMSI particles smaller than the original SMSI particles occurred.

• Research Organization: Exxon Res. Eng. Co.
• OSTI ID: 6320518
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 59:2; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical &amp; Physicochemical Properties
ADSORPTION
CHALCOGENIDES
CHEMICAL BONDS
CHEMICAL REACTIONS
CORRELATIONS
CRYSTAL STRUCTURE
DISPERSIONS
ELECTRON MICROSCOPY
ELEMENTS
FILMS
METALS
MICROSCOPY
OXIDES
OXYGEN COMPOUNDS
PLATINUM
PLATINUM METALS
POWDERS
REDUCTION
SORPTION
STRUCTURAL CHEMICAL ANALYSIS
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS