Investigation of the Impact of Chloride Contamination on Degradation in PEM Water Electrolyzer Cells

PEM water electrolysis (PEMWE) is a promising technology for hydrogen production from renewable energy sources. However, the quality of feed water significantly impacts performance and durability of PEMWE, and cost-intensive purification steps are required to reach a water resistivity of >18.2 MΩ*cm. To omit scarcity of groundwater, one major aim is to use alternative water sources, such as feed water generated by the desalination of seawater. After the desalination process, seawater still contains low amounts of ionic contaminants.
In this study, the effect of Cl− contaminants on the performance of a PEMWE single cell was tested with an accelerated stress test. After 50 h of operation, a 23% increase in the cell voltage was observed and Cl− adsorption and catalyst detachment on the electrodes were detected. The fluoride emission rate (FER), as indicator for membrane degradation, was found to be 4-fold higher for the cell exposed to the Cl− contaminant.