Surface curvature effect on single-atom sites for the oxygen reduction reaction: A model of mesoporous MOF-derived carbon

摘要

Iron-based single-atom catalysts (Fe-SACs) containing Fe-N4 active sites have shown immense potential in the oxygen reduction reaction (ORR). However, the limited ability to adsorb O2 and catalyze subsequent O-O bond breaking on Fe-N4 sites has hindered their full potential, especially in acidic electrolytes. Here, we present an approach by utilizing a tunable curved surface to enhance the activity of Fe-N4 active sites, with theoretical calculations, demonstrating that Fe-N4 sites anchored on low-curvature surfaces (lc-Fe-N4) is favirable for ORR. Experimental results show that the catalyst exhibits excellent catalytic activity and stability for ORR in acidic electrolytes, with a half-wave potential of 0.82 V vs. RHE, approaching that of commercial Pt/C. This work develops an approach for promoting the catalytic activity by anchoring atomically dispersed Fe-N4 sites, unlocking their potential for extended use in electrocatalytic and energy storage applications.

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