Elucidating activity-stability trade-offs in nano-fingerprint carbon anchoring single atoms and clusters in oxygen reduction reaction.

Li, Feng; Wu, Qikang; Zhou, Yan; Lv, Shanshan; Meng, Jing; Zhang, Yongning; Dou, Sixin; Cheng, Yanyang et al. · Nat Commun · 2026

basic_science · Level V

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Abstract

Hybrid sites (M<sub>1+x</sub>) that incorporate single atoms (M<sub>1</sub>) with clusters (M<sub>x</sub>) hold great potential for overcoming linear scaling relations in electrocatalysis, but spatial decoupling of M<sub>1</sub> from M<sub>x</sub> fundamentally hampers intercomponent synergy. Here, we report a composite electrocatalyst (Zn<sub>1</sub>Fe<sub>1+x</sub>/f-NC) featuring Fe<sub>x</sub> clusters encapsulated within nano-fingerprint carbon layers and surrounded by densely dispersed Fe/Zn-N<sub>4</sub> atomic sites. Decoupling experiments revealed that Fe<sub>1</sub>/Zn<sub>1</sub> atomic sites mainly initiate catalytic activity, while Fe<sub>x</sub> clusters further boost intrinsic activity, whereas nano-fingerprint carbon facilitates the confinement and stabilization of M<sub>1+x</sub>. The Zn<sub>1</sub>Fe<sub>1+x</sub>/f-NC demonstrates competitive oxygen reduction reaction performance, achieving a half-wave potential of 0.93 V and stability over 50 h. Zinc-air batteries with Zn<sub>1</sub>Fe<sub>1+x</sub>/f-NC air cathode exhibit a peak power density of 263.82 mW·cm<sup>-2</sup> and robust stability exceeding 2200 h at 10 mA cm<sup>-2</sup>. Density functional theory calculations reveal that the atomic Zn sites, Fe<sub>x</sub> clusters and nano-fingerprint carbon layers jointly enhance the catalytic activity and stability by modulating the electronic structure of Fe-N<sub>4</sub> sites and optimizing the adsorption energy of the key intermediate, especially OH*.