Electronic Origin and Kinetic Feasibility of the Lattice Oxygen Participation During the Oxygen Evolution Reaction on...

Density functional theory is employed to investigate the electronic origin and feasibility of surface lattice oxygen (O_surf) participation during the oxygen evolution reaction (OER) on perovskites. O_surf participation occurs via the nonelectrochemical pathway in which adsorbed atomic oxygen (O*) diffuses from the transition-metal site to the oxygen site, and then O_surf shifts out of the surface plane to react with O* to form O_surf-O* and a surface oxygen vacancy. The different thermodynamic driving forces of O_surf participation on LaMO_3-δ (M = Ni, Co, and Cu) are explained by the changes in the oxidation state of the transition-metal site throughout the reaction. We show that O_surf participation on LaNiO₃ cannot be hindered by O_surf protonation in the OER potential range. By including the coverage effect and utilizing the implicit solvent model, we finally show that lattice oxygen mechanism is more feasible than the conventional mechanism for OER on LaNiO₃.