Fe‐Regulated Coupled 2e; <sup>−</sup>; /4e; <sup>−</sup>; ORR Pathway in a Conductive Co‐Fe HITP Framework for Rechargeable Zinc‐Air Batteries | CU Experts

ABSTRACT; ; Zinc‐air batteries based on non‐precious‐metal catalysts are promising for sustainable energy conversion, yet their performance is hindered by sluggish oxygen reduction reaction (ORR) kinetics and limited understanding of pathway regulation in metal–organic framework (MOF)‐based catalysts. Herein, we report a bimetallic electron‐conductive Co‐Fe framework based on 2,3,6,7,10,11‐hexaiminotriphenylene (HITP), in which Fe incorporation shifts the ORR toward a greater four‐electron contribution. Structural, electrochemical, and density functional theory (DFT) analyses reveal complementary dual‐site roles: Co sites favor peroxide formation via the 2e; −; pathway, whereas Fe sites promote O─O bond activation and subsequent reduction of peroxide intermediates. Peroxide intermediates generated on Co sites can be further converted to OH; −; at Fe sites. As a result, the Co; 2.2; Fe; 0.8; (HITP); 2; catalyst exhibits enhanced ORR activity and enables a rechargeable zinc‐air battery with an open‐circuit voltage of 1.37 V, a peak power density of 154.2 mW cm; −2; , and a high specific capacity of 843 mAh g; Zn; −1; along with enhanced cycling stability. This work establishes electron‐conductive MOFs as a well‐defined platform for probing ORR mechanisms and highlights dual‐metal site engineering as an effective strategy for modulating ORR pathways and improving electrocatalytic performance.;

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