Structural Modification of Cobalt Catalysts: Effect of Wetting Studied by X-Ray and Infrared Techniques
The effect of wetting on the structure and localisation of cobalt species on various supports (Al2O3, SiO2, TiO2, HZSM-5 zeolite) was studied using X-ray diffraction, Fourier transform infrared spectroscopy with CO as a molecular probe, X-ray photoelectron spectroscopy and extended X-ray ab...
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EDP Sciences
1999-07-01
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Series: | Oil & Gas Science and Technology |
Online Access: | http://dx.doi.org/10.2516/ogst:1999045 |
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doaj-2cfc4b48c37e4e009c03e4af6d24adf82021-02-02T05:15:46ZengEDP SciencesOil & Gas Science and Technology1294-44751999-07-0154452553610.2516/ogst:1999045khodakov_v54n4Structural Modification of Cobalt Catalysts: Effect of Wetting Studied by X-Ray and Infrared TechniquesKhodakov A.Ducreux O.Lynch J.Rebours B.Chaumette P. The effect of wetting on the structure and localisation of cobalt species on various supports (Al2O3, SiO2, TiO2, HZSM-5 zeolite) was studied using X-ray diffraction, Fourier transform infrared spectroscopy with CO as a molecular probe, X-ray photoelectron spectroscopy and extended X-ray absorption fine structure analysis. Aqueous impregnation to incipient wetness of reduced and passivated cobalt catalysts results, even in the absence of any promoter, in a considerable decrease in the concentration of Co crystalline phases and modifies the surface sites. The decrease in the concentration of Co3O4 crystallites was especially pronounced on silica supported catalysts prepared via impregnation of cobalt and on a mixture of Co3O4 and HZSM-5 zeolite. Saturation with water of the passivated Co/SiO2 sample results in an amorphous solid with a local structure close to that of Co2SiO4. For Co/Al2O3 and Co/TiO2 catalysts, the effect of wetting on the concentration of Co3O4 crystalline phase was considerably smaller. http://dx.doi.org/10.2516/ogst:1999045 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Khodakov A. Ducreux O. Lynch J. Rebours B. Chaumette P. |
spellingShingle |
Khodakov A. Ducreux O. Lynch J. Rebours B. Chaumette P. Structural Modification of Cobalt Catalysts: Effect of Wetting Studied by X-Ray and Infrared Techniques Oil & Gas Science and Technology |
author_facet |
Khodakov A. Ducreux O. Lynch J. Rebours B. Chaumette P. |
author_sort |
Khodakov A. |
title |
Structural Modification of Cobalt Catalysts: Effect of Wetting Studied by X-Ray and Infrared Techniques |
title_short |
Structural Modification of Cobalt Catalysts: Effect of Wetting Studied by X-Ray and Infrared Techniques |
title_full |
Structural Modification of Cobalt Catalysts: Effect of Wetting Studied by X-Ray and Infrared Techniques |
title_fullStr |
Structural Modification of Cobalt Catalysts: Effect of Wetting Studied by X-Ray and Infrared Techniques |
title_full_unstemmed |
Structural Modification of Cobalt Catalysts: Effect of Wetting Studied by X-Ray and Infrared Techniques |
title_sort |
structural modification of cobalt catalysts: effect of wetting studied by x-ray and infrared techniques |
publisher |
EDP Sciences |
series |
Oil & Gas Science and Technology |
issn |
1294-4475 |
publishDate |
1999-07-01 |
description |
The effect of wetting on the structure and localisation of cobalt species on various supports (Al2O3, SiO2, TiO2, HZSM-5 zeolite) was studied using X-ray diffraction, Fourier transform infrared spectroscopy with CO as a molecular probe, X-ray photoelectron spectroscopy and extended X-ray absorption fine structure analysis. Aqueous impregnation to incipient wetness of reduced and passivated cobalt catalysts results, even in the absence of any promoter, in a considerable decrease in the concentration of Co crystalline phases and modifies the surface sites. The decrease in the concentration of Co3O4 crystallites was especially pronounced on silica supported catalysts prepared via impregnation of cobalt and on a mixture of Co3O4 and HZSM-5 zeolite. Saturation with water of the passivated Co/SiO2 sample results in an amorphous solid with a local structure close to that of Co2SiO4. For Co/Al2O3 and Co/TiO2 catalysts, the effect of wetting on the concentration of Co3O4 crystalline phase was considerably smaller.
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url |
http://dx.doi.org/10.2516/ogst:1999045 |
work_keys_str_mv |
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