Ab initio study on the adsorption of oxygen on Co(111) and its subsurface incorporation

The adsorption of oxygen on Co(111) and its subsurface incorporation is studied by density-functional theory calculations. Calculated adsorption energies, geometries and electronic structures are discussed in comparison with that of O/Co(0001). The results indicate that oxygen adsorption in hcp-hollow sites on Co(111) are the most preferred in a coverage range of 0.11–1.0 ML, and the surface electronic structure modifications for O/Co(111) points to a consistent picture of Hammer-Nørskov model. In addition, present calculations show that oxygen atoms incorporate into the first subsurface layer forming an O-Co-O trilayer on top Co(111), which possibly undergoes conversion to cobalt oxides. The behaviors of oxygen on Co(111) are similar to that of O/Co(0001)