Study of the platinum-titanium oxide system for the hydrogenation of graphite: ramifications of strong metal-support interactions
A combination of in-situ electron microscopy and surface chemical techniques (XPS, EELS) has been used to study the interaction of platinum particles with a support of mixtures of thin films of titanium oxide and graphite when treated in hydrogen. The morphological characteristics exhibited by the metal particles were strongly dependent on the location of the particles on this composite support. At temperatures near 500/sup 0/C the titanium oxide film rearranged into hexagonal-shaped islands and dendrites. Platinum particles, located on these titania regions transformed from dense globules to thin, flat structures and remained in this form up to elevated temperatures. In contrast, the metal particles on the graphite maintained their globular morphology at all temperatures; however, they subsequently exhibited two distinct patterns of behavior, depending on their proximity to titania. Two types of particles were active in catalyzing the hydrogenation of graphite, kinetic analysis showed that the intrinsic channeling rate of Pt-TiO/sub 2/ particles was three orders of magnitude faster than that of Pt particles at 1000/sup 0/PC. Consistent with these data is the finding from surface chemical analysis that a new phase is formed when Pt/TiO/sub 2//graphite specimens were treated in hydrogen at 800/sup 0/C. 22 references, 7 figures, 1 table.
- Research Organization:
- Exxon Research and Engineering Co., Annandale, NJ
- OSTI ID:
- 6014414
- Journal Information:
- J. Phys. Chem.; (United States), Vol. 90:5
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
GRAPHITE
HYDROGENATION
PLATINUM
CATALYTIC EFFECTS
TITANIUM OXIDES
AUGER ELECTRON SPECTROSCOPY
CATALYSIS
ELECTRON MICROSCOPY
ENERGY-LOSS SPECTROSCOPY
EXPERIMENTAL DATA
HIGH TEMPERATURE
HYDROGEN
PHOTOELECTRON SPECTROSCOPY
VERY HIGH TEMPERATURE
CARBON
CHALCOGENIDES
CHEMICAL REACTIONS
DATA
ELECTRON SPECTROSCOPY
ELEMENTAL MINERALS
ELEMENTS
INFORMATION
METALS
MICROSCOPY
MINERALS
NONMETALS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
SPECTROSCOPY
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
400201* - Chemical & Physicochemical Properties