Adaptation of a PEMFC Reference Electrode to PEMWE: Possibilities and Limitations

This work presents a platinum wire micro-reference electrode suitable for recording in-operando individual electrochemical impedance spectra of both the anode and the cathode in a proton exchange membrane water electrolyzer. The setup enables the protonic membrane potential to be accessed outside the active area. The reference electrode allows for the analysis of kinetic parameters for anode and cathode reactions separately. However, the exact location of the measured membrane potential is unknown due to a potentially asymmetric potential distribution, which makes the calculation of exact kinetic parameters non-trivial. Qualitative analyses of the potential distribution behavior over temperature, cell compression, and current density are shown.