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

Dual-regulation via sp-N and Co nanoparticles optimizes the Co d-band center. • Operando SERS reveals rapid interfacial *OOH conversion for efficient 4e − ORR. • CoNP/Co@sp-N breaks the inherent ORR activity-stability trade-off effectively. • Catalyst yields 0.89 V E 1/2 and enables Zn-air batteries with >240 h stability. 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. A dual-regulation strategy breaks the oxygen reduction activity-stability trade-off via a graphyne-based CoNP/Co@sp-N composite. Strong sp-hybridized nitrogen coordination ensures robust atomic anchoring, while adjacent cobalt nanoparticles electronically modulate the Co single atoms to optimize OOH binding. This synergistic architecture drives highly efficient and durable O 2 -to-H 2 O conversion for advanced zinc-air batteries. Download: Download high-res image (173KB) Download: Download full-size image