Behavior of highly-dispersed metallic iron catalysts during exposure to carbon monoxide

doi:10.1016/0304-5102(89)85047-3

Journal of Molecular Catalysis

Volume 52, Issue 3, 15 July 1989, Pages 387-396

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Abstract

The effects of the exposure to carbon monoxide of small metallic iron particles supported on carbon black, alumina and graphite were studied. The alumina- and graphite-supported samples adsorbed amounts of CO consistent with the metallic iron surface areas estimated by magnetic susceptibility. The carbon black-supported samples, however, adsorbed large amounts of CO, in some cases an average of more than three molecules per iron atom. Mössbauer spectroscopy showed that iron pentacarbonyl was formed. The formation of Fe(CO)₅ is thought to require small, coordinatively unsaturated iron particles.

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Cited by (4)

Hydrogenation of CO<inf>2</inf> and CO by Fe catalysts obtained from Fe<inf>2</inf>(CO)<inf>9</inf> and Fe<inf>3</inf>(CO)<inf>12</inf> clusters supported on activated carbons
1995, Fuel
Hydrogenation of carbon dioxide and carbon monoxide on iron catalysts prepared from Fe₂(CO)₉ and Fe₃(CO)₁₂ supported on four activated carbons were studied. The catalysts, prepared and reduced in H₂ at 673 K for 12 h, were characterized by H₂ and CO chemisorption and TEM. The catalysts prepared from Fe₃(CO)₁₂ had higher dispersion. The dispersion increased with increasing meso- and macropore volumes of the activated carbon. Hydrogenation of CO₂ produced CH₄ and CO, the rate of methane formation being much lower than that of CO formation; and both rates remained constant during reaction. However, in the hydrogenation of CO, the rate of methane formation and the CO conversion decreased with increasing reaction time, and hydrocarbons up to butane as well as CO₂ were detected among the reaction products. The differences found between the CO₂H₂ and the COH₂ reactions could be due to the different concentrations of CO surface species and to the possibility of the formation of metal oxides as a result of CO₂ dissociation.
Mo-promoted Fe/activated carbon catalysts for carbon monoxide hydrogenation
1994, Journal of Molecular Catalysis
Iron and molybdenum mono- and bimetallic catalysts supported on activated carbon have been prepared using iron pentacarbonyl and molybdenum hexacarbonyl as metal precursors. They have been characterized by temperature programmed reduction (TPR) and carbon monoxide chemisorption at 195 K and 298 K, and their catalytic activity for carbon monoxide hydrogenation at atmospheric pressure was studied under differential conditions, after reduction in hydrogen at several temperatures. Carbon monoxide chemisorption on the monometallic molybdenum catalyst was found to be strongly temperature dependent. On the other hand, the irreversible carbon monoxide chemisorption was largely decreased in the bimetallic catalyst in relation to the monometallic iron sample. The effect of molybdenum on the catalytic activity of FeMo/C is very important, producing an increase in catalytic activity which is very dependent on the reduction temperature. The selectivity of the monometallic iron catalyst is strongly modified by molybdenum addition, which produces a great increase in the yield to methane and a decrease in the alkenes to alkanes (C₂ + C₃) ratio.
Activity for ethane hydrogenolysis and carbon gasification of highly-dispersed metallic iron catalysts
1990, Journal of Molecular Catalysis
The catalytic activities of graphite-, carbon black-, alumina-, and silica-supported metallic iron catalysts for the hydrogenolysis of ethane were measured. Turnover frequencies varied over a range of three orders of magnitude. Carbon black-supported catalysts prepared from ferric nitrate had higher activities than carbon black-supported catalysts prepared from Fe3(CO)₁₂, the latter having been shown to have more spherical and possibly more widely separated metallic iron particles within the pore structure of the carbon black support. The low catalytic activity of the cluster-derived catalyst may be due to the spherical morphology of the iron particles, giving rise to highly unsaturated iron surface atoms and altering the nature of the catalytic ensembles present, or to a partial coverage of the iron surface by carbon from the support. The iron carbonyl-derived catalyst was also inactive for support gasification in hydrogen, while the conventionally-prepared catalyst almost completely gasified the carbon support during treatment in hydrogen at 773 K for 2 h.
A career in catalysis: James A. Dumesic
2021, ACS Catalysis

¹: Author to whom correspondence should be addressed.

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ArticlesBehavior of highly-dispersed metallic iron catalysts during exposure to carbon monoxide

Abstract

J. Catal.

J. Catal.

J. Catal.

J. Catal.

J. Catal.

J. Colloid Interface Sci.

Appl., Surf. Sci.

J. Catal.

J. Catal.

J. Catal.

J. Catal.

J. Catal.

Fuel

J. Catal.

J. Am. Chem. Soc.

Articles
Behavior of highly-dispersed metallic iron catalysts during exposure to carbon monoxide