Synergistic Effect of Single Atomic Ce Sites and CeO₂ Nanoparticles for Boosting Oxygen Reduction Reaction

Abstract Fe‐based single‐atomic catalysts (SACs) are considered the most promising non‐precious oxygen reduction reaction (ORR) catalysts, whereas further development is largely hindered due to the unavoidable Fenton reaction during the ORR process. Herein rare‐metal Ce‐based SACs consisting of single‐atomic Ce sites and CeO 2 nanoparticles are constructed by a facile gas‐phase migration strategy. Theoretical calculation results demonstrate that the synergistic effect of the introduction of CeO 2 and the coordination structure change of single‐atomic sites is beneficial for the decreased energy barrier of the hydrogenation step of * OH over the single‐atomic Ce sites, which contributes to the enhanced ORR performance with positive half‐wave potential of 0.88 V in 0.1 m KOH. Moreover, the assembled zinc‐air battery can deliver a high power density of 107 mW cm −2 and remarkable long‐term stability of 400 cycles at the current density of 5 mA cm −2 . This work provides a new insight for the design and construction of rare‐earth‐metal‐based SACs for the ORR.