CeO₂ Boosted Fe‐N₅ Electrocatalyst via Relay Catalysis for Modulating Oxygen Reduction Reaction in Al‐Air Batteries

Abstract Atomically dispersed iron‐nitrogen‐carbon (Fe‐N‐C) catalysts have demonstrated promising oxygen reduction reaction (ORR) activity. It poses a formidable challenge to simultaneously optimize the adsorption energies of multiple intermediates at a single active site. In addition, the lack of long‐term stability remains a significant problem due to the unavoidable 2‐electron by‐product hydrogen peroxide (H₂O₂). Here, multiple active sites are achieved to modulate the adsorption energy of intermediates while removing the by‐product of the reaction by growing the second active site CeO₂ nanoparticles in situ on the surface of the hollow‐structured Fe‐N₅, thus improving the efficiency and stability of the Fe‐N₅/CeO₂. Density functional theory (DFT) calculations are employed to probe into the synergistic catalytic interaction between Fe‐N₅ and CeO₂, proposing a relay catalytic mechanism underlying the enhanced catalytic activity. Furthermore, the catalyst stability is enhanced due to the ability of CeO₂ to scavenge the reaction by‐product and inhibit its destructive effects on the Fe‐N₅ active site. Additionally, the liquid Al – air batteries equipped with Fe‐N₅/CeO₂ display a higher power density. This work proffers an innovative vista for the conception and refinement of multi‐active‐site catalysts with excellent catalytic performance and prolonged lifespan.