Abstract:
The effects of preadsorbed hydrogen sulphide, n-propyl mercaptan, dimethyl sulphide, thiophene and carbonyl sulphide on the adsorption of carbon monoxide by silica supported nickel have been compared by study of the infrared spectra of adsorbed carbonyl species. The formation of bridged or multicentre bonded surface carbonyl species was irreversibly poisoned by all five sulphur compounds. The strength of adsorption of carbon monoxide molecules which were linearly bonded to surface nickel atoms was weakened by sulphiding of the metal. On sulphided nickel the infrared spectra are interpreted in terms of the predominant mode of adsorption involving two and possibly three carbon monoxide molecules linearly bonded to single nickel atoms. The resulting surface species are considered to be intermediates in the formation of nickel tetracarbonyl.
