Harnessing Multi‐Asymmetric Engineering: A New Horizon in Bifunctional Oxygen Electrocatalysis with Iron‐Group Atom‐Cluster Nanohybrid

Abstract Integrating active sites for oxygen reduction and evolution reactions (ORR and OER) is pivotal for advancing bifunctional oxygen electrodes. Addressing the geometric/electronic properties of these sites is essential to disrupt the linear scaling relationship between the adsorption and desorption of complex intermediates. Herein, a proof‐of‐concept is presented for constructing asymmetric trinuclear sites employing both composition‐ and size‐based asymmetric coupling strategies. These sites comprise ORR‐active Fe single atom (Fe_SA), OER‐active atomically clustered Fe species (Fe_AC), and Ni_SA sites as modulators. This Fe_AC‐SA‐Ni_SA@N‐doped carbon exhibits excellent bifunctional catalytic activities, with a narrow potential gap of 0.661 V between an ORR half‐wave potential of 0.931 V and an OER potential of 1.592 V at 10 mA cm⁻². The Zn‐air battery employing this material achieves a peak power density of 293 mW cm⁻², a specific capacity of 748 mAh g_Zn⁻¹, and remarkable stability. Experimental findings and theoretical simulations reveal that Ni_SA sites induced strong electronic coupling among the trinuclear centers, facilitating charge redistribution and optimizing the adsorption and desorption barriers for intermediates. This enhances the rapid release of ^*OH during ORR and the efficient transformation from ^*O to ^*OOH during OER. This study presents a novel strategy for developing robust bifunctional oxygen electrodes.