Dynamic X-ray diffraction study of an unreduced iron oxide catalyst in Fischer-Tropsch synthesis

Journal Article · Mon Feb 01 04:00:00 EST 1993 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1993.1033· OSTI ID:6298439

Jung, Heon; Thomson, W J ^[1]

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1. Washington State Univ., Pullman (United States)

As a result of a previous in situ DXRD study of Fischer-Tropsch synthesis over an unsupported, reduced iron catalyst, a similar study has been undertaken with an unreduced iron oxide catalyst. At 543 K and with H[sub 2]/CO = 3.2, the initial [alpha]-Fe[sub 2]O[sub 3] is immediately reduced to magnetite (Fe[sub 3]O[sub 4]), which is in turn, slowly converted to [chi]-Fe[sub 2.5]C via a shrinking core process. Catalytic activity appeared to be directly correlated with the formation of the [chi]-carbide and it is postulated that this is the catalytically active species. Significantly lower deactivation rates are observed with the unreduced iron catalyst, and it is concluded that this is due to the direct formation of [chi]-carbide in unreduced iron catalysts, which precludes the [var epsilon][prime]-carbide[yields][chi]-carbide transformation and avoids the production of the nucleate carbon arising from that transformation. 27 refs., 5 figs.

• OSTI ID: 6298439
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 139:2; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CARBIDES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
COHERENT SCATTERING
DEACTIVATION
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ELEMENTS
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HETEROGENEOUS CATALYSIS
HYDROGEN
IRON COMPOUNDS
IRON ORES
IRON OXIDES
MAGNETITE
MINERALS
NONMETALS
ORES
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
SCATTERING
STOICHIOMETRY
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION