Atomically defined iron carbide surface for Fischer-Tropsch synthesis catalysis

Yijia Li, Zheshen Li, Ali Ahsen, Lutz Lammich, Gilbère J.A. Mannie, J.W. Niemantsverdriet, Jeppe V. Lauritsen (Corresponding author)

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

With the purpose of investigating the reactivity of Fe carbide as an active phase in Fischer-Tropsch catalysis, we studied the formation of a well-defined Fe carbide surface structure resulting from carbon exposure of an Fe film on Au(111). Using two different sources of carbon (C), namely atomic carbon and ethylene gas, we used synchrotron X-ray photoelectron spectroscopy (XPS) to show that a 6 ML Fe film readily converts into a well-defined and thermodynamically stable carbide phase. Scanning tunneling microscopy (STM) showed that the surface of the Fe carbide film is crystalline and is dominated by Fe(110)-like facets perturbed into a (2 × 2) periodic structure due to insertion of C in the interstitial sites. The reactivity of the carbide film toward CO, H 2 , and O 2 was furthermore probed by XPS under vacuum conditions. While the pristine Fe carbide surface was unreactive toward hydrogen gas at 500 K, we interestingly found that CO dissociation from a preadsorbed monolayer of CO takes place already at low temperature. This observation points to an intrinsic activity of the Fe carbide phase where additional carbon originating from CO can be placed in the Fe carbide surface. The catalytic significance of the model catalyst surface presented here is that it can be seen as a stable Fe carbide phase with intrinsically vacant sites for additional C insertion at elevated pressure, and we propose that such additional C may act as active species in C-C coupling reactions during FTS. The studies pave the way for a better understanding of FTS processes on Fe-based catalysts on the basis of a well-defined model surface.

LanguageEnglish
Pages1264-1273
Number of pages10
JournalACS Catalysis
Volume9
Issue number2
DOIs
StatePublished - 1 Feb 2019

Fingerprint

Fischer-Tropsch synthesis
Catalysis
Carbides
Iron
Carbon Monoxide
Carbon
X ray photoelectron spectroscopy
Gases
iron carbide
Catalysts
Periodic structures
Scanning tunneling microscopy
Synchrotrons
Surface structure
Hydrogen
Monolayers
Ethylene
Vacuum
Crystalline materials

Keywords

  • carburization
  • Fischer-Tropsch synthesis
  • iron carbide
  • model catalyst
  • scanning tunneling microscopy
  • X-ray photoelectron spectroscopy

Cite this

Li, Y., Li, Z., Ahsen, A., Lammich, L., Mannie, G. J. A., Niemantsverdriet, J. W., & Lauritsen, J. V. (2019). Atomically defined iron carbide surface for Fischer-Tropsch synthesis catalysis. ACS Catalysis, 9(2), 1264-1273. DOI: 10.1021/acscatal.8b03684
Li, Yijia ; Li, Zheshen ; Ahsen, Ali ; Lammich, Lutz ; Mannie, Gilbère J.A. ; Niemantsverdriet, J.W. ; Lauritsen, Jeppe V./ Atomically defined iron carbide surface for Fischer-Tropsch synthesis catalysis. In: ACS Catalysis. 2019 ; Vol. 9, No. 2. pp. 1264-1273
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Li, Y, Li, Z, Ahsen, A, Lammich, L, Mannie, GJA, Niemantsverdriet, JW & Lauritsen, JV 2019, 'Atomically defined iron carbide surface for Fischer-Tropsch synthesis catalysis' ACS Catalysis, vol. 9, no. 2, pp. 1264-1273. DOI: 10.1021/acscatal.8b03684

Atomically defined iron carbide surface for Fischer-Tropsch synthesis catalysis. / Li, Yijia; Li, Zheshen; Ahsen, Ali; Lammich, Lutz; Mannie, Gilbère J.A.; Niemantsverdriet, J.W.; Lauritsen, Jeppe V. (Corresponding author).

In: ACS Catalysis, Vol. 9, No. 2, 01.02.2019, p. 1264-1273.

Research output: Contribution to journalArticleAcademicpeer-review

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AU - Li,Zheshen

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KW - Fischer-Tropsch synthesis

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KW - model catalyst

KW - scanning tunneling microscopy

KW - X-ray photoelectron spectroscopy

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Li Y, Li Z, Ahsen A, Lammich L, Mannie GJA, Niemantsverdriet JW et al. Atomically defined iron carbide surface for Fischer-Tropsch synthesis catalysis. ACS Catalysis. 2019 Feb 1;9(2):1264-1273. Available from, DOI: 10.1021/acscatal.8b03684