Unravelling the Catalytic Activity of MnO2, TiO2, and VO2(110) Surfaces by Oxygen Coadsorption on Sodium-Adsorbed MO2{M = Mn, Ti, V}

Metal-air batteries have attracted extensive research interest owing to their high theoretical energy density. However, most of the previous studies have been limited by applying pure oxygen in the cathode, without taking into consideration the effect of the catalyst, which plays a significant role in the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Adsorption of oxygen on (110) Na-MO2is investigated, using density functional theory (DFT) calculations, which is important in the discharging and charging of Na-air batteries. Adsorption of oxygen on Na/MO2was investigated, and it was observed that the catalysts encourage the formation of the discharge product reported in the literature, i.e., NaO2. The surface NaO2appears to have bond lengths comparable to those reported for monomer NaO2