Point-to-Point Orientation Aligns P-Tailored Fe-N₅ Motifs within Hierarchical Carbon Nanoreactors for Superior Oxygen Electrocatalysis in Zn-Air Batteries.

Abstract

The precise integration of atomically dispersed active sites into engineered carbon architectures for the oxygen reduction reaction (ORR) remains challenging. Herein, we introduce a novel point-to-point orientation strategy that enables the precise engineering of P-tailored Fe-N₅ motifs within raspberry-like hierarchical carbon nanoreactors (P/Fe-N-HCNCs) for oxygen electrocatalysis in Zn-air batteries. The deliberately designed hierarchical architecture ensures efficient three-dimensional mass transfer, guaranteeing access to active sites. The second-shell P-coordination tailors an electron-asymmetric environment around Fe, optimizing the adsorption free energy of *OOH intermediates and accelerating the ORR kinetics. Consequently, the P/Fe-N-HCNCs delivers an exceptional half-wave potential of 0.94 V vs RHE along with outstanding stability. When deployed in a Zn-air battery, it achieves a peak power density of 271.4 mW cm^-2 and an impressive specific capacity of 816 mA h g^-1, surpassing most reported nonprecious metal catalysts. This work establishes a general design principle synergizing atomic coordination and nanoarchitecture engineering.