Synthesis and ex‐situ evaluation of quaternized polysulfone as an anion exchange ionomer for AEM technologies

Abstract Anion exchange ionomer (AEI) is a critical component used on anion exchange membrane fuel cell (AEMFC) and alkaline water electrolyzer (AWE). In this work, quaternized polysulfone with different functionalization degree were used as an ionomer to evaluate the performance in the oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR), both implied in the operation of AEMFC and AWE. The synthesized ionomer exhibited a better performance in both reactions in comparison to the commercial AEI Aemion®. PSf‐130 exhibited better performance, since IEC and surface area increases twice regarding the same parameters in the PSf‐60. The PSf‐130 conductivity increases three times regarding the value exhibited by PSf‐60. Finally, the J lim and J k increases 67% and 100% for ORR. On the other hand, the same catalytic parameter increased 44% and 35% for HOR comparing both polysulfone‐based ionomers. The Tafel slope values do not showed drastically changes for different ionomers indicating the same rate determining step (RDS) and the same mechanism in both reactions for all the ionomers.