Robust oxygen reduction electrocatalysis via dioxygen-bridged cobalt diatomic sites scaffolded by hierarchically porous nanoarchitectures.

The rational design of dual-atom catalysts is pivotal for overcoming the intrinsic limitations imposed by Sabatier scaling relations in conventional single-atom catalysts. Herein, we present a homo-binuclear macrocyclic complex-mediated strategy for constructing cobalt-based diatomic catalysts, in which dioxygen-bridged cobalt dual-atom sites (Co-O2-Co) are uniformly embedded within hierarchically porous carbon nanospheres (denoted Co-O2-Co/HPCN) to promote efficient oxygen reduction reaction (ORR) catalysis. Notably, the hierarchically porous architecture, derived via a sacrificial-template approach, provides abundant and interconnected micro/mesopores that effectively confine the cobalt binuclear complex precursor, ensuring the atomic dispersion and structural integrity of Co-O2-Co sites. Importantly, the unique Co-O2-Co coordination motif stabilizes the *OOH intermediate through side-on bridge adsorption, thereby facilitating O-O bond cleavage and breaking the conventional *OOH-*OH scaling relationship. Benefiting from this synergistic structural and electronic modulation, Co-O2-Co/HPCN achieves an onset potential of 1.016 V and a half-wave potential of 0.916 V, surpassing commercial Pt/C catalysts. Moreover, Co-O2-Co/HPCN exhibits high power density and outstanding durability in both aqueous and flexible quasi-solid-state zinc-air batteries, underscoring its promise for next-generation energy technologies. This work establishes a robust molecular-to-material design platform for developing high-performance dual-atom catalysts and delivers atomic-level insights into optimizing sustainable energy conversion.