Role of preferential weak hybridization between the surface-state of a metal and the oxygen atom in the chemical adsorption mechanism

Abstract

We report on the chemical adsorption mechanism of atomic oxygen on the Pt(111) surface using angle-resolved-photoemission spectroscopy (ARPES) and density functional calculations. The detailed band structure of Pt(111) from ARPES reveals that most of the bands near the Fermi level are surface-states. By comparing band maps of Pt and O/Pt, we identify that d(xz) (d(yz)) and d(z)2 orbitals are strongly correlated in the surface-states around the symmetry point M and K, respectively. Additionally, we demonstrate that the s- or p-orbital of oxygen atoms hybridizes preferentially with the d(xz) (d(yz)) orbital near the M symmetry point. This weak hybridization occurs with minimal charge transfer.