Catalytic oxidation of carbon monoxide over Ru/SiO/sub 2/. An in situ infrared and kinetic study

Journal Article · Thu Mar 01 04:00:00 EST 1984 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j150649a014· OSTI ID:6704566

Kiss, J T; Gonzalez, R D

The partial deactivation of a series of Ru/SiO/sub 2/ catalysts during the CO oxidation reaction has been studied by using in situ infrared spectroscopy. The decrease in catalytic activity was fast in an oxygen-rich reactant gas mixture. At a CO/O/sub 2/ ratio greater than that required for stoichiometry, partial deactivation was slow, continuing for several hours. When the rate of the oxidation reaction was decreased following 100% conversion in the diffusion-controlled kinetic regime, a significant decrease in the reaction rate was observed. This reaction rate hysteresis was considerably larger when the catalyst was exposed to an oxygen-rich reactant gas mixture. During catalyst deactivation, the absorbance of the IR doublet centered at 2130 and 2060 cm/sup -1/ was observed to increase. This IR doublet, asssigned to CO absorbed on an oxidized Ru surface species, increased very rapidly when the reactant gas mixture was either net oxidizing or close to stoichiometry. The results of a temperature-programmed desorption (TPD) and a temperature-programmed oxidation study suggest that partial deactivation occurs as the result of the formation of a more tightly bound oxygen species, perhaps lattice oxygen which reacts more slowly with adsorbed CO than oxygen in the reactant gas mixture. Multiple steady-state oscillations were observed following the attainment of steady-state reaction rates. The results of a temperature-programmed reduction study show that the CO species responsible for the CO absorption band at 2010 cm/sup -1/ reacts preferentially with H/sub 2/ to form CH/sub 4/.

• Research Organization: Univ. of Rhode Island, Kingston
• OSTI ID: 6704566
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 88:5; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

090121* -- Hydrocarbon Fuels-- Chemical Synthesis-- (1976-1989)
10 SYNTHETIC FUELS
ALKANES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYSIS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
DATA
ELEMENTS
EXPERIMENTAL DATA
HYDROCARBONS
HYDROGENATION
INFORMATION
KINETICS
METALS
METHANE
MINERALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDATION
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
REACTION KINETICS
RUTHENIUM
SILICA
SILICON COMPOUNDS
SILICON OXIDES
SYNTHESIS
TEMPERATURE EFFECTS
TRANSITION ELEMENTS