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

Abstract

The oxidation of CO on Rh/SiO/sub 2/ has been studied by using an in situ infrared cell reactor. The catalytic activity for the rate of CO oxidation was shown to decrease in the sequence Rh(0) > Rh(I) > Rh(Iapprox.III). The results of a temperature-programmed-oxidation study show that both linearly adsorbed (2065 cm/sup -1/) and bridge-bonded (1920 cm/sup -1/) CO react with O/sub 2/ at a faster rate than the CO dicarbonyl species (2092, 2033 cm/sup -1/). A higher oxidation state of Rh, presumably Rh(Iapprox.III), which gave rise to an adsorbed CO species absorbing at 2103 cm/sup -1/, was found to be relatively inactive. The results of a temperature-programmed-reduction study show that the adsorbed CO dicarbonyl species can be converted into the linearly adsorbed species by the addition of H/sub 2/ at room temperature. Unlike Ru/SiO/sub 2/ and Pt/SiO/sub 2/, reaction rate hysteresis did not occur. However, in an oxygen-rich reactant gas mixture, some modification of the reaction rate did occur as a result of the formation of Rh(I). This led to a modest catalyst deactivation. Both heat-transfer effects and diffusion-controlled processes occur at high CO conversions. Meaningful kinetic parameters can only be obtained by considering steady-state conversions which are lessmore » than 10%.« less

Authors:
;
Publication Date:
Research Org.:
Univ. of Rhode Island, Kingston
OSTI Identifier:
6697840
Resource Type:
Journal Article
Journal Name:
J. Phys. Chem.; (United States)
Additional Journal Information:
Journal Volume: 88:5
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CARBON MONOXIDE; OXIDATION; RHODIUM; CATALYTIC EFFECTS; SILICA; CATALYSIS; EXPERIMENTAL DATA; CARBON COMPOUNDS; CARBON OXIDES; CHALCOGENIDES; CHEMICAL REACTIONS; DATA; ELEMENTS; INFORMATION; METALS; MINERALS; NUMERICAL DATA; OXIDE MINERALS; OXIDES; OXYGEN COMPOUNDS; PLATINUM METALS; SILICON COMPOUNDS; SILICON OXIDES; TRANSITION ELEMENTS; 400201* - Chemical & Physicochemical Properties

Citation Formats

Kiss, J T, and Gonzalez, R D. Catalytic oxidation of carbon monoxide over Rh/SiO/sub 2/. An in situ infrared and kinetic study. United States: N. p., 1984. Web. doi:10.1021/j150649a015.
Kiss, J T, & Gonzalez, R D. Catalytic oxidation of carbon monoxide over Rh/SiO/sub 2/. An in situ infrared and kinetic study. United States. https://doi.org/10.1021/j150649a015
Kiss, J T, and Gonzalez, R D. Thu . "Catalytic oxidation of carbon monoxide over Rh/SiO/sub 2/. An in situ infrared and kinetic study". United States. https://doi.org/10.1021/j150649a015.
@article{osti_6697840,
title = {Catalytic oxidation of carbon monoxide over Rh/SiO/sub 2/. An in situ infrared and kinetic study},
author = {Kiss, J T and Gonzalez, R D},
abstractNote = {The oxidation of CO on Rh/SiO/sub 2/ has been studied by using an in situ infrared cell reactor. The catalytic activity for the rate of CO oxidation was shown to decrease in the sequence Rh(0) > Rh(I) > Rh(Iapprox.III). The results of a temperature-programmed-oxidation study show that both linearly adsorbed (2065 cm/sup -1/) and bridge-bonded (1920 cm/sup -1/) CO react with O/sub 2/ at a faster rate than the CO dicarbonyl species (2092, 2033 cm/sup -1/). A higher oxidation state of Rh, presumably Rh(Iapprox.III), which gave rise to an adsorbed CO species absorbing at 2103 cm/sup -1/, was found to be relatively inactive. The results of a temperature-programmed-reduction study show that the adsorbed CO dicarbonyl species can be converted into the linearly adsorbed species by the addition of H/sub 2/ at room temperature. Unlike Ru/SiO/sub 2/ and Pt/SiO/sub 2/, reaction rate hysteresis did not occur. However, in an oxygen-rich reactant gas mixture, some modification of the reaction rate did occur as a result of the formation of Rh(I). This led to a modest catalyst deactivation. Both heat-transfer effects and diffusion-controlled processes occur at high CO conversions. Meaningful kinetic parameters can only be obtained by considering steady-state conversions which are less than 10%.},
doi = {10.1021/j150649a015},
url = {https://www.osti.gov/biblio/6697840}, journal = {J. Phys. Chem.; (United States)},
number = ,
volume = 88:5,
place = {United States},
year = {1984},
month = {3}
}