Elucidating the Role of Hydroxide Electrolyte on Anion-Exchange-Membrane Water Electrolyzer Performance

Many solid-state devices, especially those requiring anion conduction, often add a supporting electrolyte to enable efficient operation. The prototypical case is that of anion-exchange-membrane water electrolyzers (AEMWEs), where addition an alkali metal solution improves performance. However, the specific mechanism this performance improvement currently unknown. This work investigates functionality in AEMWEs using experiments and mathematical models. results show additional hydroxide plays key role not only ohmic resistance membrane catalyst layer but also reaction kinetics. modeling suggests added liquid creates electrochemical interface with electrocatalyst provides ion-transport pathways distributes product gas bubbles; total effective active surface area cell 1 M KOH 5 times higher than DI water. In KOH, more 80% current associate electrolyte. These indicate importance high pH catalyst/electrolyte AEMWEs. understanding presented study should help guide design optimization