Ionomer Optimization for Hydroxide-Exchange-Membrane Water Electrolyzers Operated with Distilled Water: A Modeling Study

The hydroxide-exchange-membrane water electrolyzer (HEMWE) is a promising means to store intermittent renewable energy in the form of hydrogen chemical energy. hydroxide-exchange ionomer (HEI) gas-evolving electrodes and membrane (HEM) are key components HEMWE. In this work, we simulate cell examine explicitly impact HEI HEM properties with focus on improving HEMWE performance when operated distilled ( i.e ., no supporting electrolyte). tradeoff between ionic conductivity gain electrochemically active surface area (ECSA) loss studied. For constant catalyst loading, distributing more next or making thinner but denser layer beneficial for performance. results demonstrate that higher diffusion coefficient desired supply reactant cathode. contrast, lower preferred cathode retain regions high reaction rates. Overall, findings provide important insights optimizing HEI/HEM materials improved