A quantitative determination of reaction mechanisms from density functional theory calculations: Fischer-Tropsch synthesis on flat and stepped cobalt surfaces

Jun Cheng, Xue-Qing Gong, P. Hu*, C. Martin Lok, Peter Ellis, Sam French

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

141 Citations (Scopus)

Abstract

We systematically investigated the mechanism of the C-1 + C-1 coupling reactions using density functional theory. The activation energies of C-1 + C-1 coupling and carbon hydrogenation reactions on both flat and stepped surfaces were calculated and analyzed. Moreover, the coverages of adsorbed C-1 species were estimated, and the reaction rates of all possible C-1 + C-1 coupling pathways were quantitatively evaluated. The results suggest that the reactions of CH2 + CH2 and CH3 + C at steps are most likely to be the key C-1 + C-1 coupling steps in FT synthesis on Co catalysts. The reactions of C-2 + C-1 and C-3 + C-1 coupling also were studied; the results demonstrate that in addition to the pathways of RCH + CH2 and RCH2 + C, the coupling of RC + C and RC + CH also may contribute to the chain growth after C-1. (C) 2008 Elsevier Inc. All rights reserved.

Original languageEnglish
Pages (from-to)285-295
Number of pages11
JournalJournal of Catalysis
Volume254
Issue number2
Early online date11 Feb 2008
DOIs
Publication statusPublished - 10 Mar 2008

Keywords

  • Fischer-tropsch
  • DFT
  • Co
  • mechanism
  • C-C coupling
  • electron-energy-loss
  • carbon-monoxide
  • AB-initio
  • methane decomposition
  • rate coefficients
  • CO dissociation
  • metal-surfaces
  • chain growth
  • catalysts
  • CO(0001)

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