Article révisé par les pairs
Résumé : The effect of atom coordination and influence of an external electrostatic field on binding and dissocn. energies of mol. oxygen on a nano modified Au surfaces are investigated. Weak O and O2 adsorption are found in our models. A considerable decrease of the dissociation energy of O2 was found when adsorbed on small gold clusters or gold pyramids. It is concluded that in the presence of an electric field no dissociation of O2 will occur in our model. This result is in agreement with field ion microscopy (FIM) and field electron microscopy (FEM) experiments, where no dissociation of O2 is encountered.