Self-Adjustment of Intrinsic Reaction Intermediate on Atomically Dispersed Co2-N6 Binuclear Sites Achieving Boosted Electrocatalytic Oxygen Reduction Performance

Isolated dual-atom catalysts (DACs) have sparked enormous research enthusiasm in new energy community due to their great potentials to substitute the state-of-the-art Pt-based catalysts. Nevertheless, explicitly unraveling the underlying catalytic mechanisms is of critical significance for performance enhancement, yet remains a huge challenge. Herein, the study reports a reliable hard template-mediated strategy to accomplish the construction of atomically isolated binuclear Co-2-N-6 sites stabilized by ultrathin hollow carbon nanospheres (abbreviated as Co-2-DAs@CHNSs). Systematic spectroscopy characterization and theoretic calculations uncover that the Co-2-N-6 sites follow a self-adjusting mechanism caused by the intrinsic OH intermediate. The involvement of the -OH energy-level modifier is found to induce the electron redistribution and alternation of antibonding orbital fillings for the generated Co-2-N-6-OH site, leading to reduced potential-determining step (PDS) energy barrier, and thus boosted intrinsic activity. Consequently, the well-managed Co-2-DAs@CHNSs afford outstanding oxygen reduction reaction (ORR) activity with a half-wave potential of 0.87 V in alkaline electrolyte, overmatching the Pt benchmark. Furthermore, the Co-2-DAs@CHNSs-assembled aqueous and all-solid-state rechargeable zinc-air batteries (ZABs) demonstrate high power density, large specific capacity, and robust stability. The findings offer an innovative avenue to rationally manipulate the electronic structures of active sites for DACs via a powerful self-ligand modification strategy.