Hydrogen crossover measurement and durability assessment of high-pressure proton exchange membrane electrolyzer

The crossover of hydrogen in a high pressure proton exchange membrane (PEM) hydrogen electrolyzer needs to be taken into account because it affects both energy consumption and safety. And hydrogen crossover measurements at actual operating temperature and pressure conditions are necessary. Hydrogen crossover rates based on pressure data at a cathode pressure of 11.3 MPa, an anode pressure of atmospheric pressure, and a current density of 0.4 A/cm2 have been studied to evaluate the potential of operating a high pressure differential PEM electrolyzer. The degradation phenomenon of the electrolyzer before and after the high pressure experiments has been investigated by both performance testing and material morphology characterization. Irreversible plastic deformation due to strong mechanical extrusion and possible impurity adsorption on the surface of the anode catalyst layer result in a significant performance degradation. •Time-saving activation method of catalyst coated membrane is proposed.•Pressure-based in situ measurement of hydrogen crossover is proposed.•The degradation of the electrolyzer due to high pressure is investigated.