The electrolysis of water through the use of renewable energy is the most advanced technology for the production of "green" hydrogen for a variety of applications including transport, heat and electricity production and industrial uses. In this context, alkaline liquid-electrolyte water electrolysis (AWE) is currently one of the least costly technologies for water splitting from renewable power sources. The most used water electrolysis systems are, generally, based on porous diaphragm separators and liquid alkaline electrolytes, leading to high corrosion of the setup components. To avoid this problem, the research is moving on the development of anion exchange membrane aiming good performance and durability. [1,2]

Thanks to their unique characteristics of chemical, thermal and electrochemical stability, perfluorinated polymers are proposed as an alternative to hydrocarbon-based anion exchange membranes (AEMs) for applications in water electrolysers. In this work, we report a simple two-step functionalization reaction to introduce quaternary ammonium groups onto Aquivion® backbone. A study of the best dispersant agent and reaction time was performed. The complete conversion of the precursors into a quaternary ammonium salt is confirmed by solid-state NMR. Physico-chemical parameters at temperatures higher than conventional (T>60°C) were measured, thermal behaviour and anion conductivity of the formed AEM were investigated. After immersion in alkaline solution, a very limited degradation of functional groups is demonstrated, showing only 2% of ion exchange capacity (IEC) reduction. An electrolysis current density of 0.9 A cm-2 at 2.2 V and 90 °C with a voltage efficiency of 70 % is achieved, showing to be a very promising material for green hydrogen production (Figure 1). [3]