Preparation and characterization of partial-cocrystallized catalyst-coated membrane for solid polymer electrolyte water electrolysis

A novel catalyst-coated membrane (CCM) for solid polymer electrolyte water electrolysis was fabricated by together crystallizing partial-crystallized Nafion membrane and catalyst layers. The properties and performance of the partial-cocrystallized CCM (PCCCM) were evaluated and analyzed by destructive soaking test, scanning electron microscope, mercury intrusion and single cell test. The results revealed that the optimum annealing temperature and time for fabricating partial-crystallized Nafion membrane and PCCCM was 100 °C for 4 h and 120 °C for 4 h, respectively. The PCCCM not only possessed much stronger cohesion between membrane and catalyst layers, but also had higher porosity than conventional CCM. The electrolysis voltage of the SPE water electrolyser with the new CCM was as low as 1.748 V at 2000 mA cm−2 under 80 °C and atmospheric pressure. Moreover, there was no obvious increase of electrolysis voltage during stability test conducted under 2000 mA cm−2 for about 180 h.