Assessment of the FAA3-50 polymer electrolyte in combination with a NiMn2O4 anode catalyst for anion exchange membrane water electrolysis

A commercial FAA3-50 membrane was investigated as a solid polymer electrolyte in an alkaline water electrolysis. An improved chemical treatment based on alkaline KOH solution was carried out. A limited degradation of the functional groups was observed allowing to maintain a good anion conductivity approaching 55 mS cm-1 at 100 °C. Thermal stability up to 200 °C was assessed by thermal analysis. A specific membrane-electrodes assembly based on FAA3-50 anionic membrane and NiMnO anode catalyst was developed and investigated in a single cell for water electrolysis at a moderate temperature (50 °C). Performance stability was assessed by a potential cycling-based durability test for 1000 h by varying the cell potential between 1 and 1.8 V for the FAA3-50 and NiMnO based-MEA. According to this evaluation, both the FAA3-50 membrane and the NiMnO catalyst appear sufficiently stable for electrolysis operation under mild operating temperatures.