Review—Reference Electrodes in Proton Exchange Membrane Water Electrolysis: Previous Approaches, Current Application, and Perspectives

Abstract

The commercialization of proton exchange membrane water electrolysis cells (PEMWEs), which are essential for a greener and more sustainable future, is hindered by the high costs of noble metal catalysts, as well as the degradation of the catalysts and membranes. Examining the electrodes' characteristics with reference electrodes (REs) yields insights into their individual performance and can, e.g., help assess new catalyst layer designs, their interplay with the adjacent porous transport layer, or understand the complex and multi-faceted degradation mechanisms. This review provides an overview of previous approaches and the evolution of RE designs in PEMWE. By discussing the strengths and limitations of different RE setups, readers are enabled to make more informed decisions about their experiments' design and choose the best RE setup for their specific research question.

Analysis of Kinetic and Ohmic Resistances in PEM Water Electrolysis through Reference Electrode Measurements

“…1 is available in ealier publications of this group. 6,11 Besides measuring the voltages, electrochemical impedance spectroscopy can measure the high frequency resistance. This measurement gives the full cell HFR and the half-cell values R A-RE and R C-RE :…”

“…This allows for an improved loss breakdown, enabling the attribution of measured overpotentials to their sources. 6 Various RE configurations have been reported in the literature, such as embedding a reversible hydrogen electrode (RHE) within the membrane, positioning an RHE on the membrane outside of the active area, or establishing a connection between an external RE to the potential of the membrane or catalyst layer. [7][8][9][10] This study investigates the latter approach.…”