title: 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.
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.
authors.affiliation: School of Chemistry, University of Glasgow, Joseph Black Building, Glasgow, Scotland G12 8QQ, United Kingdom.
authors.forename: Robbie
authors.initials: R
authors.lastname: Warringham
authors.affiliation: School of Chemistry, University of Glasgow, Joseph Black Building, Glasgow, Scotland G12 8QQ, United Kingdom.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: McFarlane
authors.affiliation: School of Physics and Astronomy, University of Glasgow, The Kelvin Building, Glasgow, Scotland G12 8QQ, United Kingdom.
authors.forename: Donald A
authors.initials: DA
authors.lastname: MacLaren
authors.affiliation: Sasol Technology UK Ltd., Purdie Building, North Haugh, St Andrews, Fife KY16 9ST, United Kingdom.
authors.forename: Paul B
authors.initials: PB
authors.lastname: Webb
authors.affiliation: Sasol Technology UK Ltd., Purdie Building, North Haugh, St Andrews, Fife KY16 9ST, United Kingdom.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Tooze
authors.affiliation: ISIS Facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, United Kingdom.
authors.forename: Jon
authors.initials: J
authors.lastname: Taylor
authors.affiliation: ISIS Facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, United Kingdom.
authors.forename: Russell A
authors.initials: RA
authors.lastname: Ewings
authors.affiliation: ISIS Facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, United Kingdom.
authors.forename: Stewart F
authors.initials: SF
authors.lastname: Parker
authors.affiliation: School of Chemistry, University of Glasgow, Joseph Black Building, Glasgow, Scotland G12 8QQ, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Lennon
mesh_terms: D002248:Carbon Monoxide / Q000737:chemistry*; D002384:Catalysis; D005290:Ferric Compounds / Q000737:chemistry*; D006865:Hydrogenation; D008280:Magnetics; D046529:Microscopy, Electron, Transmission; D009502:Neutrons; D013059:Spectrum Analysis, Raman
chemical_list: D005290:Ferric Compounds; C000499:ferric oxide; D002248:Carbon Monoxide