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 (H 2 O 2 ). 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 CeO 2 nanoparticles in situ on the surface of the hollow‐structured Fe‐N 5 , thus improving the efficiency and stability of the Fe‐N 5 /CeO 2 . Density functional theory (DFT) calculations are employed to probe into the synergistic catalytic interaction between Fe‐N 5 and CeO 2 , proposing a relay catalytic mechanism underlying the enhanced catalytic activity. Furthermore, the catalyst stability is enhanced due to the ability of CeO 2 to scavenge the reaction by‐product and inhibit its destructive effects on the Fe‐N 5 active site. Additionally, the liquid Al – air batteries equipped with Fe‐N 5 /CeO 2 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.