Hamilton, Neil G.; Silverwood, Ian P.; Warringham, Robbie; Kapitan, Josef; Hecht, Lutz; Webb, Paul B.; Tooze, Robert P.; Parker, Stewart F.; Lennon, David

Angewandte Chemie, International Edition (2013), 52(21), 5608-5611 CODEN: ACIEF5; ISSN: 1433-7851. English.

This work has, for the first time, used inelastic neutron scattering (INS) to obtain the vibrational spectrum of a tech.-grade Fe-based Fischer-Tropsch (F-T) catalyst that was taken from a large-scale unit operation. The vibrational spectra, elemental anal., temperature programmed oxidation, and the matrix assisted laser desorption/ionization time of flight data are all consistent with the presence of an overlayer of amorphous carbon, which is supplemented to a minor extent with a hydrocarbonaceous component. INS data imply approx. equal nos. of H atoms bonded to sp2 and sp3 hybridized C atoms. The specific role of this previously unconsidered species in F-T process chem. is unproven but is tentatively attributed to moderating reagent transfer at the catalyst surface. Addnl. INS expts. are planned to further explore the validity of this enticing hypothesis.