Platinum and palladium-catalyzed gasification of carbon by hydrogen, water, and carbon dioxide

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1982

OSTI ID:6475045

Holstein, W L

Both the Pt-catalyzed and uncatalyzed hydrogenolysis of C to CH/sub 4/ were studied at temperatures above and below 1050/sup 0/K and at H/sub 2/ pressures between ca. 10 and 100 kPa. At 890/sup 0/K and atmospheric pressure, Pt accelerated the reaction rate by a factor of 2000. Studies of kinetic isotope effects and reaction orders suggest rapid equilibration of the C surface with H/sub 2/ followed by a rate-determining step involving breaking of a C-C bond in the uncatalyzed reaction. However, with Pt, the rate-determining step seems to lead to the formation of a C-Pt bond with subsequent reaction of the carbidic C on Pt. Differential rates and integral surface time yields of the uncatalyzed and Pt-catalyzed gasification of C by H/sub 2/O and CO/sub 2/ were measured above and below 950/sup 0/K and at pressures below atmospheric. Even though both reactions were inhibited by their products, at 890/sup 0/K the catalyzed reactions were about 100 times faster than the uncatalyzed. Isotope effect studies of the gasification using H/sub 2/O/H/sub 2/ and H/sub 2/O/O/sub 2/ suggest equilibration of the Pt surface with adsorbed O/sub 2/ which yields CO by reaction with C that has been transported to the Pt surface following breakage of C-C bonds at the Pt-C interface. Results of studies on the interaction of Pd and amorphous C in vacuo and in CO/sub 2/ at pressure of about 120Pa and at about 1150/sup 0/K indicate that the Pd particles (10-300nm) catalyze the conversion of amorphous C to a more graphitic form as observed by electron diffraction. DISS. ABSTR. INT., B

• OSTI ID: 6475045
• Country of Publication: United States
• Language: English

Related Subjects

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010403 -- Coal & Coal Products-- Hydrogenation-- (-1987)
010404 -- Coal
Lignite
& Peat-- Gasification
090121* -- Hydrocarbon Fuels-- Chemical Synthesis-- (1976-1989)
10 SYNTHETIC FUELS
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400302 -- Organic Chemistry-- Isotope Effects-- (-1987)
ALKANES
CARBON
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
COAL GASIFICATION
DEUTERIUM
ELEMENTS
GASIFICATION
HYDROCARBONS
HYDROGEN ISOTOPES
HYDROGENATION
ISOTOPE EFFECTS
ISOTOPES
LIGHT NUCLEI
METALS
METHANE
NONMETALS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PALLADIUM
PLATINUM
PLATINUM METALS
STABLE ISOTOPES
STEAM
SYNTHESIS
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENTS