The effect of decomposition atmosphere on the activity and selectivity of the carbonyl cluster derived Co/SiO2 and Rh/SiO2 catalysts

Jari Kiviaho (Corresponding Author), Marita Niemelä, Matti Reinikainen, T. Vaara, Tapani Pakkanen

Research output: Contribution to journalArticleScientificpeer-review

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Abstract

The effect of pretreatment atmosphere, hydrogen or carbon monoxide, on the activity and selectivity of the Rh4(CO)12/SiO2 and Co4(CO)12/SiO2 catalysts in CO hydrogenation was determined. The catalysts pretreated under hydrogen exhibited a higher degree of decomposition of the original cluster, higher hydrogen uptake and lower carbon content than those decomposed under CO. Therefore, some of the active sites of the catalysts were encapsulated by carbon, and in the case of Co4(CO)12 poorly reducible cobalt silicates were probably also formed. The activity of the hydrogen-treated Rh4(CO)12/SiO2 was fairly similar to that of the CO-treated catalyst, but significantly fewer oxygenates were formed. Thus, the carbon monoxide treatment appeared to facilitate the formation of oxygenates. Probably the original structure of rhodium carbonyl was better retained, and thereby some of the rhodium particles remained more dispersed under CO than under hydrogen. In the case of Co4(CO)12/SiO2 catalysts, however, no benefit was observed in conjunction with CO pretreatment either in activity or selectivity. Most likely the CO treatment resulted in the formation of unreactive carbonaceous species which permanently blocked most of the active sites.

Original languageEnglish
Pages (from-to)1 - 8
Number of pages8
JournalJournal of Molecular Catalysis A: Chemical
Volume121
Issue number1
DOIs
Publication statusPublished - 1997
MoE publication typeA1 Journal article-refereed

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Hydrogen
selectivity
Decomposition
decomposition
catalysts
atmospheres
Catalysts
hydrogen
Rhodium
Carbon Monoxide
rhodium
Carbon monoxide
pretreatment
carbon monoxide
Carbon
Silicates
carbon
Cobalt
Hydrogenation
hydrogenation

Cite this

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title = "The effect of decomposition atmosphere on the activity and selectivity of the carbonyl cluster derived Co/SiO2 and Rh/SiO2 catalysts",
abstract = "The effect of pretreatment atmosphere, hydrogen or carbon monoxide, on the activity and selectivity of the Rh4(CO)12/SiO2 and Co4(CO)12/SiO2 catalysts in CO hydrogenation was determined. The catalysts pretreated under hydrogen exhibited a higher degree of decomposition of the original cluster, higher hydrogen uptake and lower carbon content than those decomposed under CO. Therefore, some of the active sites of the catalysts were encapsulated by carbon, and in the case of Co4(CO)12 poorly reducible cobalt silicates were probably also formed. The activity of the hydrogen-treated Rh4(CO)12/SiO2 was fairly similar to that of the CO-treated catalyst, but significantly fewer oxygenates were formed. Thus, the carbon monoxide treatment appeared to facilitate the formation of oxygenates. Probably the original structure of rhodium carbonyl was better retained, and thereby some of the rhodium particles remained more dispersed under CO than under hydrogen. In the case of Co4(CO)12/SiO2 catalysts, however, no benefit was observed in conjunction with CO pretreatment either in activity or selectivity. Most likely the CO treatment resulted in the formation of unreactive carbonaceous species which permanently blocked most of the active sites.",
author = "Jari Kiviaho and Marita Niemel{\"a} and Matti Reinikainen and T. Vaara and Tapani Pakkanen",
year = "1997",
doi = "10.1016/S1381-1169(96)00451-7",
language = "English",
volume = "121",
pages = "1 -- 8",
journal = "Journal of Molecular Catalysis A: Chemical",
issn = "1381-1169",
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The effect of decomposition atmosphere on the activity and selectivity of the carbonyl cluster derived Co/SiO2 and Rh/SiO2 catalysts. / Kiviaho, Jari (Corresponding Author); Niemelä, Marita; Reinikainen, Matti; Vaara, T.; Pakkanen, Tapani.

In: Journal of Molecular Catalysis A: Chemical, Vol. 121, No. 1, 1997, p. 1 - 8.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - The effect of decomposition atmosphere on the activity and selectivity of the carbonyl cluster derived Co/SiO2 and Rh/SiO2 catalysts

AU - Kiviaho, Jari

AU - Niemelä, Marita

AU - Reinikainen, Matti

AU - Vaara, T.

AU - Pakkanen, Tapani

PY - 1997

Y1 - 1997

N2 - The effect of pretreatment atmosphere, hydrogen or carbon monoxide, on the activity and selectivity of the Rh4(CO)12/SiO2 and Co4(CO)12/SiO2 catalysts in CO hydrogenation was determined. The catalysts pretreated under hydrogen exhibited a higher degree of decomposition of the original cluster, higher hydrogen uptake and lower carbon content than those decomposed under CO. Therefore, some of the active sites of the catalysts were encapsulated by carbon, and in the case of Co4(CO)12 poorly reducible cobalt silicates were probably also formed. The activity of the hydrogen-treated Rh4(CO)12/SiO2 was fairly similar to that of the CO-treated catalyst, but significantly fewer oxygenates were formed. Thus, the carbon monoxide treatment appeared to facilitate the formation of oxygenates. Probably the original structure of rhodium carbonyl was better retained, and thereby some of the rhodium particles remained more dispersed under CO than under hydrogen. In the case of Co4(CO)12/SiO2 catalysts, however, no benefit was observed in conjunction with CO pretreatment either in activity or selectivity. Most likely the CO treatment resulted in the formation of unreactive carbonaceous species which permanently blocked most of the active sites.

AB - The effect of pretreatment atmosphere, hydrogen or carbon monoxide, on the activity and selectivity of the Rh4(CO)12/SiO2 and Co4(CO)12/SiO2 catalysts in CO hydrogenation was determined. The catalysts pretreated under hydrogen exhibited a higher degree of decomposition of the original cluster, higher hydrogen uptake and lower carbon content than those decomposed under CO. Therefore, some of the active sites of the catalysts were encapsulated by carbon, and in the case of Co4(CO)12 poorly reducible cobalt silicates were probably also formed. The activity of the hydrogen-treated Rh4(CO)12/SiO2 was fairly similar to that of the CO-treated catalyst, but significantly fewer oxygenates were formed. Thus, the carbon monoxide treatment appeared to facilitate the formation of oxygenates. Probably the original structure of rhodium carbonyl was better retained, and thereby some of the rhodium particles remained more dispersed under CO than under hydrogen. In the case of Co4(CO)12/SiO2 catalysts, however, no benefit was observed in conjunction with CO pretreatment either in activity or selectivity. Most likely the CO treatment resulted in the formation of unreactive carbonaceous species which permanently blocked most of the active sites.

U2 - 10.1016/S1381-1169(96)00451-7

DO - 10.1016/S1381-1169(96)00451-7

M3 - Article

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JF - Journal of Molecular Catalysis A: Chemical

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