Approaches to Mitigate Electrochemical Ionomer Oxidation

Hydrogen production through anion-exchange membrane water electrolyzers (AEMWEs) presents cost advantages compared to proton-exchange membrane equivalents, thanks to the heightened oxygen evolution reaction (OER) efficiency of platinum-group-metal-free catalysts in alkaline environments. However, the electrochemical oxidation of ionomers at the OER catalyst interface leads to a decrease in local electrode pH, which hampers AEMWE performance. Various strategies at the single-cell level have been explored to tackle this challenge. This article delves into the current understanding of electrochemical ionomer oxidation and its alleviation methods, offering our perspective on each approach. Our analysis emphasizes the efficacy of the competitive adsorption strategy in mitigating ionomer oxidation. This perspective piece also outlines future pathways for advancing high-performance alkaline AEMWEs and other energy devices utilizing hydrocarbon ionomers.