Pressurized operation of anion exchange membrane water electrolysis

Water electrolyzers that use an anion exchange membrane (AEM) are expected to be new devices for hydrogen (H2) production that achieve high performance at low capital cost. Such an AEM electrolyzer could produce pressurized H2 as easily as does as a proton exchange membrane (PEM) electrolyzer. In this study, H2 pressure in an AEM electrolyzer was increased to 8.5 bars in the cell. Here, the effect of such high H2 pressure on electrolysis performance was verified by simultaneously measuring the dependency of several parameters on current density during pressurized operation; parameters such as cell voltage, cell resistance, H2 content in the anode gas, H2 production rate, and water content in the produced H2. Results also revealed that pressurized operation of AEM electrolysis offered the advantage of low humidity H2 production, with minimal degradation in the electrolysis performance.