Voltage Loss Analysis of Proton Exchange Membrane Water Electrolyzers

Abstract

Proton exchange membrane water electrolyzers (PEMWEs) present a promising hydrogen production alternative to common methods like steam methane reforming, particularly for producing green hydrogen from renewable sources. However, scaling up PEM electrolyzers is challenged by the high cost of their platinum group metal catalysts (Ir & Pt) for the oxygen and hydrogen evolution reactions (OER & HER). This study focused on the performance of PEM electrolyzers and its subsequent volage loss breakdown analysis. Current voltage loss breakdown analyses separate voltage losses into three categories: kinetic, ohmic, and mass transport overpotentials. Current models explain the first two but lack proper phenological description of the latter. To better separate and ascribe the mass transport losses due to electrode and PTL dry-out, a new electrolyzer galvanostatic intermittent titration technique (eGITT) was developed in this work. The time-series data from this pulse-based transient diagnostic evaluated through time-scale analysis and basic physical models to extract key transport properties that can be used to quantify the efficacy of different electrode and PTL materials. Results from this method were compared to current model predictions and evaluated against literature values.