Argon Microwave Plasma Processed Electrodeposited FeCo Catalysts on Ti Paper as an Anode Porous Transport Layer (PTL) for Cathode-Dry Anion Exchange Membrane Water Electrolysis (AEMWE)

ED-FeCo/TP is synthesized by the electrochemical deposition of FeCo on titanium fiber paper (TP) as the catalyst for the oxygen evolution reaction (OER) in cathode-dry operation anion exchange membrane water electrolysis (AEMWE). With 15 s Ar microwave plasma (ArMP) treatment, the catalytic performance is enhanced. The ED-FeCo/TP treated with ArMP (ED-FeCo/TP-ArMP15) exhibits an overpotential of 459 mV@100 mA/cm2 and an improved Tafel slope of 211.1 mV/dec, a higher double-layer capacitance (2.80 mF/cm2), a lower charge transfer resistance (1.10 Ω), and enhanced electrochemical activity. ArMP treatment provides a reduction effect, leading to the formation of abundant metallic Fe0 and Co0 in ED-FeCo/TP-ArMP15. The cathode-dry AEMWE system with ArMP treatment (Ru/CP(−)//ED-FeCo/TP-ArMP15(+)) exhibits better performance at higher current densities than the system without ArMP treatment (Ru/CP(−)//ED-FeCo/TP(+)). When applied as the anode in a cathode-dry AEMWE system operated at 70 °C, the cell voltage at a current density of 500 mA/cm2 decreases from 1.88 V for ED-FeCo/TP to 1.79 V for ED-FeCo/TP-ArMP15. These results indicate that ArMP treatment effectively enhances the OER efficiency.