Activating Lattice Oxygen Redox of Co 3 O 4 through Rare‐Earth‐Excited Electron Self‐Donation for Improving Electrocatalytic Oxygen Evolution

Abstract Designing high‐efficiency transition‐metal oxides for catalyzing the oxygen evolution reaction (OER) necessitates the activation of lattice oxygen to avoid the arduous adsorbate evolution pathway, yet significant challenges still remain. Herein, a rare‐earth (RE)‐excited electron self‐donation strategy is proposed to activate lattice oxygen of Co 3 O 4 , and thus bypassing the thermodynamically limited adsorbate evolution pathway. The RE‐Co 3 O 4 (RE: Yb, Y, Gd, Tb) catalysts are synthesized by ZIF‐67‐derived coordination method, enabling the atomic‐level substitution of RE into Co 3 O 4 hollow spheres (HS). The synthetic RE‐Co 3 O 4 exhibits improved electrocatalytic activity toward OER compared with commercial RuO 2 , where Yb‐Co 3 O 4 presents the best OER activity with a low overpotential of 272 mV and an excellent electrocatalytic stability. The pH‐dependent test and in situ Raman measurements demonstrate that the introduction of Yb exposes more surface negative O sites and facilitates proton transfer kinetics, thus promoting the lattice‐oxygen‐assisted O 2 release. Theoretical analysis corroborates that the [Yb‐O‐Co] site reveals the electron self‐donation toward coordinated O to lead the activation, where the over‐accumulated charge at lattice O sites guides the direct O─O coupling with lower energy gap. Furthermore, the Zn‐air battery equipped with Yb‐Co 3 O 4 ‐HS + Pt/C as the cathode delivers a large specific capacity (731 mAh g −1 ) and an enhanced discharge/charge process, demonstrating its excellent practical application.