(221e) A High Performing Alkaline Water Electrolyzer

Water electrolyzers are being developed as a way of storing renewable energy, as a way to produce hydrogen for fuel cell automobiles, and as a route to renewable fuels and chemicals. In this paper, we demonstrate alkaline water electrolyzers with iron/nickel/cobalt catalysts that show 1 A/cm² at 60 °C. The performance is stable for 2000 hours, showing only 3-5 µV/hr degradation. Key to the findings is the development of new Sustainion™ alkaline exchange membranes that show high conductivity and good stability in 1 M KOH.

These results show that the use of Sustainion™ membranes allow one to greatly improve the performance of alkaline water electrolyzers. While the initial voltage is higher than a typical PEM electrolyzer with platinum/iridium catalysts, the stability is better, so after 1000 hours or so, the performance is quite similar. This presents the possibility of one replacing rare materials such as iridium with iron and nickel, and still maintaining high currents and the ability to turn the system on and off quickly.