Synergistic Strong-Weak Adsorption Coupling in the FeN ₆ –CoN ₄ Dual-Site Modulates Oxygen Reduction Pathways via Oxygen Adsorbate Evolution-to-Dissociation Transition

Atomically dispersed non-noble metal–nitrogen-carbon electrocatalysts could derive a four-electron oxygen reduction reaction (ORR) described via a typical adsorbate evolution mechanism (AEM), but their kinetics are limited by the linear scaling relationship (LSR) between the *OOH and *OH. Herein, we reported heteronuclear dual-site FeN 6 –CoN 4 materials obtained via integrating Fe 3+ and Co 2+ into pyrrole-functionalized g-C 3 N 4 nanosheets. Such electrocatalysts broke the conventional LSR through a shifted oxygen dissociation mechanism (ODM: *O 2 → *O + *OH → 2 *OH). Density functional theory calculations confirmed the strongest and weakest adsorption strengths of key ORR intermediates in the CoN 4 and FeN 6 sites with a conventional AEM pathway. Under the synergistic effect of dual-site strong-weak adsorption, FeN 6 –CoN 4 switched from ORR pathways to the ODM observed via in situ infrared spectroscopy for the rate-determining step (*O 2 → *O + *OH) with the decreased overpotentials of 0.41 V (FeN 6 ) and 0.50 V (CoN 4 ), enhancing intrinsic ORR kinetics. A Zn–air battery based on FeN 6 –CoN 4 demonstrated an open-circuit voltage of 1.65 V approaching the theoretical 1.68 V, high-power density of 314 mW cm –2, and durable discharge at 500 mA cm –2 . This work provides fundamental insights into dual-site synergy for regulating ORR pathways, offering a strategy for designing efficient atomic catalysts.