First principles study of adsorption of O2 on Al surface with hybrid functionals.

Adsorption of O(2) molecule on Al surface has been a long standing puzzle for the first principles calculation. We have studied the adsorption of O(2) molecule on the Al(111) surface using hybrid functionals. In contrast to the previous local-density approximation/gradient-corrected approximation, the present calculations with hybrid functionals successfully predict that O(2) molecule can be absorbed on the Al(111) surface with a barrier around 0.2-0.4 eV, which is in good agreement with experiments. Our calculations predict that the lowest unoccupied molecular orbital of O(2) molecule is higher than the Fermi level of the Al(111) surface, which is responsible for the barrier of the O(2) adsorption.