Effects of coverage on the structures, energetics, and electronics of oxygen adsorption on $RuO2(110)$ Available to Purchase

Plane-wave supercell DFT calculations within the PW91 generalized gradient approximation are used to examine the influence of oxygen coverage on the structure, energetics, and electronics of the $RuO2(110)$ surface. Filling of $Obr$ and $Ocus$ sites is exothermic with respect to molecular $O2$ at all coverages and causes changes in local Ru electronic structure consistent with the changing metal coordination. By fitting the surface energies of a large number of surface configurations to a two-body interaction model, an O atom is calculated to be bound by $2.55eV$ within a filled $Obr$ row and by $0.98eV$ along an otherwise vacant $Ocus$ row. Lateral interactions modify these binding energies by up to 20%. $Ocus–Ocus$ interactions are repulsive and diminish binding energy with increasing $Ocus$ filling. Due to the favorable relief of local strain, $Obr–Obr$ interactions are attractive and favor filling of neighbor br sites. These interaction effects are relatively modest in absolute magnitude but are large enough to influence the ability of the $RuO2(110)$ surface to promote oxidation of relatively weak reductants, such as NO and $C2H4$⁠.