John Kitchin, Department of Chemical Engineering, Carnegie Mellon University, 5000 Forbes Ave, 3112 Doherty Hall, Pittsburgh, PA 15213
The adsorption energy of many atomic adsorbates such as O and S on the (111) surfaces of late transition metal surfaces is dependent on the coverage and detailed configuration of the adsorbed oxygen atoms. We have used density functional theory to calculate the adsorption energy of atomic adsorbates in the fcc hollow sites on several late transition metal (111) surfaces at coverages up to 1 ML. In all cases we have found that the adsorption energy decreases with increasing coverage, but that the coverage dependence is metal dependent. We have traced the metal dependence to how the surface d-band structure is modified by the adsorbates and found that this adsorbate-induced surface electronic structure is surface dependent and linearly dependent on coverage. The linear correlations between the coverage, surface electronic structure and adsorption energies leads to linear correlations between the adsorption energies of each adsorbate configuration on each surface. Most significantly, each of these linear correlations can be reduced to a single, universal correlation that describes the adsorption of oxygen and sulfur in the fcc hollow sites on all the late transition metal surfaces. We will discuss the implications of this principle of corresponding adsorption states on the adsorbate phase diagrams of these adsorbates.