Operando Impedance Spectroscopy Informed Dynamic Internal Resistance Compensation Mitigates Bubble-Induced...

Bubble formation during gas-evolving electrochemical reactions disrupts potential control and obscures intrinsic catalyst-performance relationships. While conventional strategies to mitigate this issue have relied on surface engineering or cell design, here we introduce a dynamic internal resistance (IR) compensation approach that adapts to bubble-induced fluctuations in real time. This was achieved by employing (i) operando electrochemical impedance spectroscopy (EIS), which provided the electrolyte resistance (R _Ohm) parameter continuously, and (ii) a Python control loop to extract EIS data and dynamically adjust the IR compensation. This self-correcting approach effectively suppressed bubble-induced artifacts during prolonged electrochemical CO₂ reduction (ECO₂R) on copper, enabling accurate performance evaluation and reliable assessment of catalyst instability under realistic operating conditions. We argue that such control is essential in ECO₂R stability studies, where even minor potential shifts can obscure intrinsic catalyst-performance relationships and hinder mechanistic insight into degradation.