CO dissociation on Ni(100) studied by Auger electron spectroscopy

Auger Electron Spectroscopy (AES) has been used to investigate the kinetics of CO dissociation on a Ni(100) single crystal surface. The coverages of carbidic carbon and oxygen on the surface have been monitored as a function of time for different sample temperatures (453 K ≤ T ≤ 573 K) and CO pressures (3 × 10−7 mbar ≤ PCO ≤ 3 × 10−6 mbar). The experimental data have been compared to the results of rate equations relative to different dissociation models. This procedure led to the identification of the probable reaction mechanism, whose most relevant step in this pressure range resulted to be the rupture of the CO bond. The activation energy of the process has been evaluated.