Adsorption of Atomic and Molecular Oxygen on the Au(321) Surface:  DFT Study

Spin-polarized density functional theory based calculations within the GGA/PW91 exchange-correlation functional have been carried out to investigate the interaction of atomic and molecular oxygen on the Au(321) surface modeled by a periodic supercell approach. It was found that the atoms prefer interaction with surface cavities, while in the case of molecules, adsorption is more favorable if the molecular axis is parallel to the surface terraces on bridge or nearby bridge sites. Further, the interaction of separated atoms with the Au(321) surface may well induce, at a relatively low energetic cost, strong surface relaxation. The dissociation of molecular oxygen on the Au(321) surface is exothermic, and the barrier for the dissociation reaction, determined using the climbing-image nudged elastic band method, is 1.00 eV and with an interatomic oxygen distance for the transition states of ∼1.91 Å.