Opportunities of Ionomer Development for Anion-Exchange Membrane Water Electrolysis

Anion-exchange membrane water electrolysis (AEM-WE) promises low cost, green hydrogen production for the future. In order to meet this potential, significant improvements to the performance and stability of catalyst layers (CLs) must be made, including the development of tailor-made ion conducting polymer materials. This Focus Review outlines the role of anion-exchange ionomers (AEIs) in CLs for enabling catalyst activation, enhancing stability toward delamination, and improving ion conduction. Detrimental effects such as inhibition of the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) and oxidative instability of the ionomer are also discussed with key findings from recent AEM-WE literature. Opportunities for future ionomer development are discussed to guide such efforts.