Multi‐Functional Cerium Modification to Accelerate the Oxygen Reduction Reaction of Spinel Co3O4

Abstract To enhance the oxygen reduction reaction (ORR) activity of spinel Co 3 O 4 , in this work, a novel strategy of cerium (Ce) modification is developed via the co‐precipitation and followed annealing method. The Ce modification not only diminishes the critical size, but also increases the surface content of Co 3+ and elevates the conductivity of the Co 3 O 4 electrocatalysts, working together to enhance the ORR activity. Moreover, the adsorptive CeO 2 on the surface of Co 3 O 4 further promotes the ORR activity by the synergistic effect between CeO 2 and Co 3 O 4 . Typically, the optimized 0.5 % Ce−Co 3 O 4 exhibits a half‐wave potential of 0.665 V versus reversible hydrogen electrode (RHE) and low Tafel slope of −60 mV dec −1 as well as long‐term stability.