Facet‐Dependent Oxygen Reduction Reaction Activity on the Surfaces of Co₃O₄

The mechanisms for oxygen reduction reaction (ORR) on the naturally exposed (110) and (111) surfaces of Co₃O₄ have been investigated with density functional theory (DFT) calculations. Depending on the vertical cutting place, there are type A and B surfaces for each of the (110) and (111) surfaces of Co₃O₄. Our DFT calculations reveal that the Co₃O₄ (110) type B and (111) type B surfaces have ORR catalytic activities. In addition, the ORR activity on the (110) type B surface is better than the (111) type B surface. The rate‐determining step on both surfaces is thermodynamically depending on the *OH desorption process. If the solvation effects are taken into accounts, the chemically adsorbed water molecules enhance the ORR activity. According to the barrier heights calculations, O₂ → *O₂ → *OOH → *O + H₂O → *OH → H₂O route is the most favorable ORR pathway.