Hydrogen production by water electrolysis with an ultrathin anion-exchange membrane (AEM)

A new ultrathin anion exchange membrane (AEM) is proposed for low cost AEM electrolysis. The advantages that thin membranes offer include reduced mass transport resistance and ohmic resistance. A membrane electrode assembly (MEA) with a thinner membrane will have improved hydroxide ion transfer due to the shorter ion transfer pathway. We fabricated a MEA with a commercially available ultrathin A-901 membrane (9 μm thick) and non-noble metal catalysts. We determined the efficiency and stability of this ultrathin membrane using electrochemical impedance spectroscopy. The best performance recorded was 400 mA cm^-2 at 1.94 V at 50 °C. Over a period of 200 h, the voltage increase was only 200 μV h^-1, which is <60% that of the more commonly used A-201 membrane. The ultrathin A-901 membrane exhibited slightly higher performance compared to the A-201 for a given catalyst, catalyst loading, and electrolyte concentration. Acta 3030® (CuCoO_x) and Acta 4030® (Ni/(CeO₂-La₂O₃)/C) were employed as the oxygen evolution reaction and hydrogen evolution reaction catalysts, respectively.