Study of the carburization of an iron catalyst during the Fischer-Tropsch synthesis: influence on its catalytic activity
The fast transformation of an ironalumina catalyst into Fe/sub 2+x/C during the H/sub 2/ + CO reaction was followed by in situ Moessbauer spectroscopy at 523 K and the behavior was compared with changes in catalytic activity for Fischer-Tropsch synthesis. After a few hours of synthesis, no metallic iron could be detected by either Moessbauer or IR spectroscopy, whereas the CO conversion was still half of that observed initially. The nature of the sites responsible for the remaining activity is discussed. The interpretation of the Moessbauer spectra has permitted the determination of the stoichiometry of the Fe/sub 2+x/C carbide (0 less than or equal to x less than or equal to 0.4), and hence the following of the change of x during the reaction. Thus, the activity in CO hydrogenation could be related to the number of carbon vacancies in the iron carbide, i.e., to the extent of the metallic character of this carbide. This concept of the variation of hydrogenating properties of the carbide with the carbon content has been supported by similar catalytic results obtained in the room temperature hydrogenation of ethylene performed on carbides of different stoichiometry
- Research Organization:
- l'Universite Claude Bernard Lyon I, Villeurbanne (France)
- OSTI ID:
- 5330370
- Journal Information:
- J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 107:1; ISSN JCTLA
- Country of Publication:
- United States
- Language:
- English
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ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CARBIDES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CARBURIZATION
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
ELEMENTS
FISCHER-TROPSCH SYNTHESIS
HARDENING
HYDROGENATION
INFRARED SPECTRA
IRON
IRON CARBIDES
IRON COMPOUNDS
KINETICS
METALS
METHANATION
MOESSBAUER EFFECT
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
SPECTRA
SPECTROSCOPY
SURFACE HARDENING
SURFACE TREATMENTS
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS