Density functional study on the dissociation process of oxygen on the Al(111) surface

The dissociation process of an O2 molecule on the Al (111) surface was studied by calculating the potential energy surface (PES) with the density functional theory and the pseudopotential method within the generalized gradient approximation (GGA). The PES obtained has shown that the Al (111) surface attracts the O2 molecule and the molecule dissociates without any energy barrier for both end-on and side-on configurations. This result is in contrast with the experiment which has shown an activated-type adsorption of the O2 molecule. The discrepancy might be due to the insufficiency of GGA for the electron correlation or the use of the adiabatic approximation.