Characterisation of ethylene adsorption on model skeletal cobalt catalysts by inelastic and quasi-elastic neutron scattering

Abstract

To bridge the materials gap of single crystal work on the Fischer-Tropsch chain-growth mechanism, ethylene adsorption on a model skeletal cobalt catalyst was studied. Speciation and mobility of surface species were characterised using inelastic (INS) and quasi-elastic (QENS) neutron scattering. INS spectra demonstrated that highly reactive sites facilitated ethylene dehydrogenation at lower temperature than in single crystal studies. Adsorbed hydrogen was assigned to Co3H and potentially a Kubas species. After adsorption at 30 °C, methyl groups were identified. CO co-adsorption was shown to modify the dynamics of the adsorbed species. Further analysis demonstrated the sensitivity of skeletal cobalt to surface hydroxylation.