Compositional aspects of iron Fischer-Tropsch catalysts

An XPS/reaction study

C. S. Kuivila, Peter C Stair, J. B. Butt

Research output: Contribution to journalArticle

60 Citations (Scopus)

Abstract

The catalytic and compositional behaviors of prereduced and unreduced iron catalysts for Fischer-Tropsch synthesis were investigated. Catalytic behavior was evaluated by measuring rates of hydrocarbon formation in a 3:1 H2:CO mixture at 1 atm and 250 °C. Iron phases which evolved near the catalyst surfaces were characterized by X-ray photoelectron spectroscopy, and bulk phases present following reaction were determined by Mössbauer spectroscopy. At low conversion levels the prereduced catalyst was gradually converted to iron carbide with no significant oxide phase formed. Synthesis activities increased initially with the formation of active surface carbon, but eventually lost some activity due to graphitic carbon formation. At higher conversions, the prereduced catalyst showed some formation of surface oxide phases and an inhibition of the synthesis rate due to water adsorption. Surface carbon accumulation was also suppressed under these conditions. Unreduced Fe2O3 showed no initial synthesis activity, but underwent a gradual activation to become even more active than the prereduced catalyst. The oxide catalyst was eventually completely reduced to Fe3O4, and any metallic phase formed was rapidly converted to iron carbide. Compared to reduced materials, the oxide catalyst accumulated considerably less surface carbon and showed no loss of activity for reaction times up to 48 h. XPS analysis suggests that Fe3O4 is active for synthesis.

Original languageEnglish
Pages (from-to)299-311
Number of pages13
JournalJournal of Catalysis
Volume118
Issue number2
DOIs
Publication statusPublished - 1989

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Iron
X ray photoelectron spectroscopy
iron
catalysts
Catalysts
Oxides
Carbon
synthesis
oxides
carbon
carbides
Carbides
Fischer-Tropsch synthesis
Carbon Monoxide
Hydrocarbons
reaction time
Thermodynamic properties
hydrocarbons
Chemical activation
photoelectron spectroscopy

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology

Cite this

Compositional aspects of iron Fischer-Tropsch catalysts : An XPS/reaction study. / Kuivila, C. S.; Stair, Peter C; Butt, J. B.

In: Journal of Catalysis, Vol. 118, No. 2, 1989, p. 299-311.

Research output: Contribution to journalArticle

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