Chemistry and catalysis of the water gas shift reaction. 1. The kinetics over supported metal catalysts

Journal Article · Thu Jan 01 00:00:00 EST 1981 · J. Catal.; (United States)

DOI:https://doi.org/10.1002/chin.198118167· OSTI ID:6580847

Grenoble, D C ^[1]; Estadt, M M; Ollis, D F

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1. Exxon Research and Engineering Co., Linden, NJ

The kinetics of the WGS reaction as catalyzed by alumina-supported Group VIIB, VIII, and IB metals are examined. For several metals a strong effect of support on metal activity is observed. For example, the turnover number (rate per surface metal atom) of Pt supported on Al/sub 2/O/sub 3/ is an order of magnitude higher than the turnover number of Pt on SiO/sub 2/. The turnover numbers (at 300/sup 0/C) of the various alumina-supported metals studied for WGS decrease in the order Cu, Re, Co, Ru, Ni, Pt, Os, Au, Fe, Pd, Rh, and Ir. For these metals the range of activity varies by more than three orders of magnitude. It is shown that a volcano-shaped correlation exists between the activities of these metals and their respective CO heats of adsorption. The partial pressure dependencies of the reactants on these metals are reported for the first time. Over most metals the CO order of reaction is near zero and the H/sub 2/O order of reaction is near 1/2. A reaction sequence including formic acid as an intermediate is proposed in order to account for the apparent bifunctionality of the supported catalyst systems. This approach leads to a power rate law, r = kP/sub CO/sup x/P/sub H2O/sup 1-X)/2//, an expression shown to be consistent with the experimental parameters obtained in these kinetic studies.

• OSTI ID: 6580847
• Journal Information: J. Catal.; (United States), Vol. 67:1
• Country of Publication: United States
• Language: English

Related Subjects

08 HYDROGEN
COBALT
CATALYTIC EFFECTS
COPPER
GOLD
IRON
NICKEL
PLATINUM METALS
WATER GAS PROCESSES
CATALYSIS
ADSORPTION HEAT
ALUMINIUM OXIDES
CARBON MONOXIDE
CATALYSTS
CHEMICAL REACTION KINETICS
CORRELATIONS
HYDROGEN PRODUCTION
PRESSURE DEPENDENCE
SUPPORTS
ALUMINIUM COMPOUNDS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
ELEMENTS
ENTHALPY
KINETICS
MECHANICAL STRUCTURES
METALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
REACTION KINETICS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENTS
080104* - Hydrogen- Production- Water Gas Processes