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 language | English |
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Pages (from-to) | 285-295 |
Number of pages | 11 |
Journal | Journal of Catalysis |
Volume | 254 |
Issue number | 2 |
Early online date | 11 Feb 2008 |
DOIs | |
Publication status | Published - 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)