Using density functional theory, we investigate the difference in the reactive pathways and potential-energy surfaces for the dissociative adsorption of oxygen $\left({\mathrm{O}}_2\right)$ on platinum (Pt) and gold (Au) surfaces. We found that the reactivity on Au surface can be improved by changing the surface structure. However, it does not exceed that on Pt surface. We also found that the difference of the reactivity can be attributed to the affinity between metal surface and oxygen atom, and not between metal surface and oxygen molecule. This conclusion is further corroborated by our calculated atom-projected density of states results, which show that the difference in reactivity comes from the difference in the hybridization strength between electrons of oxygen and those of the metal surface.

• Received 23 July 2007

DOI:https://doi.org/10.1103/PhysRevB.77.115413