Unveiling the structure-function relationships of ionomer for water electrolysis by neutron reflectometry

Hydrogen, recognized as one of the most promising, exceptionally efficient, and environmentally friendly clean energy resources, plays a crucial role in shaping the future of sustainable energy. However, traditional water splitting technologies are not yet cost effective. In recent years, one of the most encouraging approaches to produce clean hydrogen is low temperature electrolysis using single-ion-conducting polymers (ionomers), which provides the best opportunity for dynamic and high-current operation and offers system-efficiency gains via differential pressure operation.[1-3] Nevertheless, a lack of holistic understanding of the ionomer interfacial phenomena (e.g., interfacial molecular structure change, critical thickness for electrochemical performance) hinders current progress in this technology.[4] Thus, our proposal is targeted to address this issue by means of fundamentally investigating the complex ionomer interaction with catalyst, its structuration at the catalysts surface, in the typical operation conditions of water electrolyzer. A deep understanding from the atomic and macroscopic level could allow the rational design of the materials, assemblies, and operating conditions for improving the efficiency, durability, and cost effectiveness of water electrolysis.