Non‐planar Nest‐like [Fe2S2] Cluster Sites for Efficient Oxygen Reduction Catalysis

Metal‐nitrogen‐carbon catalysts, as promising alternative to platinum‐based catalysts for oxygen reduction reaction (ORR), are still highly expected to achieve better performance by modulating the composition and spatial structure of active site. Herein, we constructed the non‐planar nest‐like [Fe2S2] cluster sites in N‐doped carbon plane. Adjacent double Fe atoms effectively weaken the O−O bond by forming a peroxide bridge‐like adsorption configuration, and the introduction of S atoms breaks the planar coordination of Fe resulting in greater structural deformation tension, lower spin state, and downward shifted Fe d‐band center, which together facilitate the release of OH* intermediate. Hence, the non‐planar [Fe2S2] cluster catalyst, with a half‐wave potential of 0.92 V, displays superior ORR activity than that of planar [FeN4] or [Fe2N6]. This work provides insights into the co‐regulation of atomic composition and spatial configuration for efficient oxygen reduction catalysis. Non‐planar nest‐like [Fe2S2] cluster sites in N‐doped carbon plane with similar active center atomic composition to ferredoxin achieve efficient O2 adsorption and activation while avoiding too robust adsorption of OH* intermediate, thus realizing excellent oxygen reduction reaction (ORR) performance beyond planar [FeN4] and [Fe2N6]. This work provides insights into co‐regulation of atomic composition and spatial configuration for efficient ORR catalysis.