First-principles study of interaction between oxygen and Pt surface

The interaction between oxygen and Pt(111) surface has been investigated and the O–Pt(111) surface phase diagram has been calculated via first-principles methods and thermodynamics. The results indicate that, in thermal equilibrium, the oxygen surface phases are 2×22×2, for oxygen partial pressures throughout a range from relatively low to high values. Our results reveal that indirect long-range O–O interactions, soft-mode anharmonic vibrations of the Pt-atoms induced by oxygen atoms, and surface distortions are responsible for the 2×22×2 configuration of oxygen atoms on Pt(111) surface. Our results do not just reveal physical phenomena specific to Pt surfaces, but also further basic understanding of how adatoms interact with each other and with metal surfaces.