Jump to main content
Jump to site search

Issue 9, 2014
Previous Article Next Article

Quantum chemistry of the Fischer–Tropsch reaction catalysed by a stepped ruthenium surface

Author affiliations

Abstract

A comprehensive density functional theory study of the Fischer–Tropsch mechanism on the corrugated Ru(11[2 with combining macron]1) surface has been carried out. Elementary reaction steps relevant to the carbide mechanism and the CO insertion mechanism are considered. Activation barriers and reaction energies were determined for CO dissociation, C hydrogenation, CHx + CHy and CHx + CO coupling, CHxCHy–O bond scission and hydrogenation reactions, which lead to formation of methane and higher hydrocarbons. Water formation that removes O from the surface was studied as well. The overall barrier for chain growth in the carbide mechanism (preferred path CH + CH coupling) is lower than that for chain growth in the CO insertion mechanism (preferred path C + CO coupling). Kinetic analysis predicts that the chain-growth probability for the carbide mechanism is close to unity, whereas within the CO insertion mechanism methane will be the main hydrocarbon product. The main chain propagating surface intermediate is CH via CH + CH and CH + CR coupling (R = alkyl). A more detailed electronic analysis shows that CH + CH coupling is more difficult than coupling reactions of the type CH + CR because of the σ-donating effect of the alkyl substituent. These chain growth reaction steps are more facile on step-edge sites than on terrace sites. The carbide mechanism explains the formation of long hydrocarbon chains for stepped Ru surfaces in the Fischer–Tropsch reaction.

Graphical abstract: Quantum chemistry of the Fischer–Tropsch reaction catalysed by a stepped ruthenium surface

Back to tab navigation

Supplementary files

Publication details

The article was received on 14 Apr 2014, accepted on 27 May 2014 and first published on 19 Jun 2014


Article type: Paper
DOI: 10.1039/C4CY00483C
Author version
available:
Download author version (PDF)
Citation: Catal. Sci. Technol., 2014,4, 3129-3140
  • Open access: Creative Commons BY license
  •   Request permissions

    Quantum chemistry of the Fischer–Tropsch reaction catalysed by a stepped ruthenium surface

    I. A. W. Filot, R. A. van Santen and E. J. M. Hensen, Catal. Sci. Technol., 2014, 4, 3129
    DOI: 10.1039/C4CY00483C

    This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material.

    Reproduced material should be attributed as follows:

    • For reproduction of material from NJC:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
    • For reproduction of material from PCCP:
      [Original citation] - Published by the PCCP Owner Societies.
    • For reproduction of material from PPS:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
    • For reproduction of material from all other RSC journals:
      [Original citation] - Published by The Royal Society of Chemistry.

    Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.

Search articles by author

Spotlight

Advertisements