DOI: 10.1002/adsc.70721 ISSN: 1615-4150

Unveiling the Microkinetic Origin of Negative Impedance in Oxygen Reduction Electrocatalysis: A Pulse‐Potential Strategy for Enhanced Activity

Yu Gao, Wanying Liu, Yan Li, Xueying Ji, Shiming Zhang

By developing a microkinetic model for the associative oxygen reduction reaction (ORR), we reveal that negative impedance in electrochemical impedance spectroscopy (EIS) arises under specific combinations of electrode potential and hydroxyl binding energy (). This phenomenon stems from dynamic competition between intermediate adsorption/desorption and charge transfer, with the coverage relaxation playing a dominant role. Crucially, the frequency range of negative impedance is correlated with the intrinsic timescale of the coverage relaxation and can serve as a guide for selecting the perturbation frequency in pulse‐potential experiments. We thus establish an impedance‐guided dynamic modulation framework and demonstrate that applying a square‐wave potential pulse with this optimal frequency window can selectively enhance the time‐averaged ORR current by dynamically mitigating adsorbate poisoning. This work bridges EIS signatures to ORR microkinetics and establishes a general, impedance‐guided framework for rationally designing pulsed‐potential protocols. This approach transforms EIS from a passive diagnostic tool into an active design compass for boosting catalytic performance beyond static limits.

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