Relating the coverage dependence of oxygen adsorption on Au and Pt fcc(1Â 1Â 1) surfaces through adsorbate-induced surface electronic structure effects

Using density functional theory (DFT) we studied the adsorption of oxygen on gold and platinum fcc (1 1 1) surfaces as a function of coverage. We show how increasing coverages of oxygen atoms lead to a broadening of the surface atom d-bands and a consequent reduction in the average energy of the d-band center due to conservation of the d-band filling. The reduction in the energy of the d-band center leads to a correlated increase (weakening) in the adsorption energy. This underlying electronic structure relationship exists on both the gold and platinum surfaces, and we show that the coverage dependent adsorption energies of oxygen on these two surfaces are related by a simple near-linear correlation.