Abstract
We have investigated adsorption and subsequent dissociation of oxygen molecules on the NiO surface with and without vacancies by ab initio molecular dynamics simulation to understand the elementary process of the oxygen reduction reaction in the SOFC cathode. Oxygen molecules were adsorbed both on the surfaces with and without vacancy. However, dissociation was confirmed only on the surface with oxygen vacancy. It is because positive charge of the Ni atoms near the oxygen vacancy was smaller than that without vacancy and electron of adsorbed oxygen molecules is transferred toward the Ni atoms resulting in the decrease of the strength of O-O bond in the oxygen molecule.
