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

To enhance the oxygen reduction reaction (ORR) activity of spinel Co3O4, 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 Co3+ and elevates the conductivity of the Co3O4 electrocatalysts, working together to enhance the ORR activity. Moreover, the adsorptive CeO2 on the surface of Co3O4 further promotes the ORR activity by the synergistic effect between CeO2 and Co3O4. Typically, the optimized 0.5 % Ce-Co3O4 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.

Automated summary

By modifying with cerium (Ce), the critical size of spinel Co3O4 is reduced, the surface content of Co3+ is increased, and the conductivity is improved to enhance the ORR activity. Additionally, the adsorptive CeO2 on the surface of Co3O4 further promotes the ORR activity through a synergistic effect.