PFAS-Free: Robust and Chemically Stable Ion-Solvating Polymer Membrane Derived from Poly(arylene alkylene) for High-Performance Alkaline Water Electrolysis

Polymeric ion-solvating membranes 1 derived from poly(arylene alkylene)s 2 have emerged as promising candidates for alkaline water electrolysis, offering a PFAS-free, robust, and chemically stable alternative. This work focuses on the development of such a membrane with an emphasis on high resistance to gas crossover, addressing the challenges associated with conventional ion-exchange materials. The polymer membrane presented in this study demonstrated very good performance in alkaline water electrolysis. At 80 degrees Celsius, the membrane exhibits a specific conductivity of 36 mS/cm, underscoring its ion-solvating ability and efficiency in a 20 wt% KOH solution. The electrochemical performance is exemplified by the attainment of a 700-mA current below 2.6V with uncatalyzed nickel foam electrodes, showcasing the superior conductivity and efficiency in facilitating the electrolysis process. One of the key features of these membranes is their longevity, as evidenced by their ability to operate for more than 200 hours without any discernible voltage decay. This extended operational lifespan underscores the robustness and durability of the developed membranes, making them highly suitable for practical applications in alkaline water electrolysis. Furthermore, the membranes exhibit a high resistance to gas crossover, addressing a common challenge in electrolysis systems. This property ensures enhanced selectivity and efficiency by minimizing unwanted reactions and improving the overall electrolysis process. In conclusion, the presented work signifies a significant advancement in the development of ion-solvating polymer membranes derived from poly(arylene alkylene) for alkaline water electrolysis. The membranes not only outperform existing alternatives but also offer a sustainable and environmentally friendly solution by being PFAS-free. The demonstrated high performance, stability, and resistance to gas crossover make these membranes promising candidates for the advancement of alkaline water electrolysis technology, contributing to the development of efficient and environmentally conscious hydrogen production systems. Keywords: Alkaline; electrolysis; Poly (arylene alkylene)s; membranes; ion-solvating References: Aili, D.; Kraglund, M. R.; Rajappan, S. C.; Serhiichuk, D.; Xia, Y.; Deimede, V.; Kallitsis, J.; Bae, C.; Jannasch, P.; Henkensmeier, D.; Jensen, J. O. ACS Energy Lett. 2023 , 8 , 1900–1910. Zolotukhin, M. G.; Fomine, S.; Lazo, L. M.; Hernndez, M. D. C. G.; Guzmáln-Gutiérrez, M. T.; Ruiz-Trevino, A.; Fritsch, D.; Cuellas, D. C.; Fernandez-G., J. M. High Perform. Polym . 2007 , 19 , 638–648.