THEORETICAL-STUDY OF THE CO INTERACTION WITH 3D-METAL SURFACES

Ab initio molecular-orbital calculations of the M-CO systems (M = Sc to Cu) combined with Pauling's resonating-valence-bond theory indicate that CO adsorption only on Sc, Ti, V, Cr, Mn, and Fe surfaces will be dissociative, and nondissociative on Co, Ni, and Cu surfaces, in agreement with the experimental evidence. The nature of the chemical bond, charge transfer, Fermi level, and other parameters of the CO interaction with 3d-metal surfaces is analyzed. The CO dissociation is described as a charge-transfer process with bonds resonating among the metal, C, and O atoms. CO dissociation in activated catalytic processes on modified 3d surfaces is discussed.