A density functional study on adsorption and dissociation of O2 on Ir(1Â 0Â 0) surface

► A density functional calculations are performed to investigate the adsorption and dissociation of O2 on Ir(1 0 0) surface. ► Dissociative adsorption is found to be energetically more favorable compared to molecular adsorption. ► Hybridization between p-O2 and d-metal orbitals play important role in the dissociation event. ► Dissociation occurs very early in the dissociation path with small activation barrier.