The application of inelastic neutron scattering to explore the significance of a magnetic transition in an iron based Fischer-Tropsch catalyst that is active for the hydrogenation of CO

J Chem Phys. 2015 Nov 7;143(17):174703. doi: 10.1063/1.4935054.

Abstract

An iron based Fischer-Tropsch synthesis catalyst is evaluated using CO hydrogenation at ambient pressure as a test reaction and is characterised by a combination of inelastic neutron scattering (INS), powder X-ray diffraction, temperature-programmed oxidation, Raman scattering, and transmission electron microscopy. The INS spectrum of the as-prepared bulk iron oxide pre-catalyst (hematite, α-Fe2O3) is distinguished by a relatively intense band at 810 cm(-1), which has previously been tentatively assigned as a magnon (spinon) feature. An analysis of the neutron scattering intensity of this band as a function of momentum transfer unambiguously confirms this assignment. Post-reaction, the spinon feature disappears and the INS spectrum is characterised by the presence of a hydrocarbonaceous overlayer. A role for the application of INS in magnetic characterisation of iron based FTS catalysts is briefly considered.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbon Monoxide / chemistry*
  • Catalysis
  • Ferric Compounds / chemistry*
  • Hydrogenation
  • Magnetics*
  • Microscopy, Electron, Transmission
  • Neutrons*
  • Spectrum Analysis, Raman

Substances

  • Ferric Compounds
  • ferric oxide
  • Carbon Monoxide