(456f) The Configurational Correlation: Relating Ab Initio Energies of Surface Oxides Across Transition Metal Surfaces

The correlation between DFT based adsorption energies of single atomic adsorbates across different transition metal surfaces has previously been demonstrated. The source of this near linear correlation is a shared electronic structure effect coverage dependence that can be observed through the modification of the surface metal's d-band structure caused by the presence of adsorbates.

One such single atomic adsorbate that follows this configurational correlation on transition metal surfaces (such as Ag, Au, Pt, and Pd) is oxygen. At low oxygen exposures chemisorbed oxygen can be observed on these surfaces, but at higher exposures, but not high enough to form bulk oxides, surface oxides are either observed or predicted. These surface oxide configurations consist of metal ad atoms sitting atop the surface in addition to adsorbed oxygen. These configurations can play an influential role in the phase behavior of these systems under a range of oxygen partial pressures, and a weakness of some ab initio studies into oxygen's phase behavior on these surfaces has been neglecting these configurations.

We show that the configurational correlation can be extended to these surface oxide configurations by examining the energies of several simple surface oxide configurations as well as several additionally experimentally relevant configurations and showing that these energies correlate across different transition metal surfaces. We also investigate the phase behavior of these surface oxide configurations and how their stability relates to the chemisorbed oxygen configurations. Lastly, we also investigate whether a common bonding mechanism can be found as the source of this correlation.