Breaking the activity-stability trade-off in oxygen reduction via sp-hybridized nitrogen/nanoparticle dual-regulation.

Single-atom catalysts have drawn massive interest for their ability to electrocatalyze the oxygen reduction reaction (ORR), primarily attributed to their ultimate atom economy and structurally distinct active centers. Nevertheless, simultaneously achieving robust durability and exceptional catalytic efficiency persists as a critical bottleneck. Herein we develop a graphyne-based composite material (CoNP/Co@sp-N) composite wherein sp-hybridized nitrogen (sp-N) anchored Co single atoms are synergistically coupled with adjacent cobalt nanoparticles. Density functional theory (DFT) reveals that while strong sp-N coordination provides robust atomic anchoring, the sp-N/nanoparticle electronic synergy precisely optimizes the Co d-band center to achieve near-ideal OOH binding, effectively decoupling the inherent ORR activity-stability trade-off. The unique coordination environment provides formidable orbital hybridization for unyielding atomic anchoring while the nanoparticle-induced electronic modulation optimizes the adsorption free energy of OOH intermediates. This synergistic integration bypasses the traditional compromise by simultaneously enhancing electrocatalytic efficiency and preserving operational stability. Notably, the CoNP/Co@sp-N composite delivers outstanding oxygen reduction performance, achieving a half-wave potential of 0.89 V, and exhibits zero efficiency loss following 5000 continuous cycles. Moreover, when incorporated into a functional zinc-air battery, this catalyst attained a peak power density of 187.33 mW cm-2 and exhibited remarkable cycling stability surpassing 240 h, thereby underscoring its significant potential for extensive energy conversion applications.