PEM electrolysis: Degradation study of N1110 assemblies for the production of green hydrogen

Abstract

The production of hydrogen through proton exchange membrane water electrolysis (PEMWE) is seen as a key solution for sustainable energy generation. However, the durability and stability of Proton Exchange Membrane (PEM) cells components, particularly Membrane-Electrode Assemblies (MEAs), remain crucial challenges to overcome for scalability. In this study, the degradation of a 25 cm2 CCM-type MEA was systematically investigated, using N1110 as the polymeric electrolyte and an anodic and cathodic loading of 3 mg/cm2 of PtB. A PEM electrolysis test bench was subjected to controlled operating conditions corresponding to 2 V and 60 °C for two stages of 168 h each, conducting a detailed analysis of performance behavior before, during, and after each degradation period. Electrochemical techniques were employed to characterize the performance stability: chronoamperometry, linear polarization curves, and electrochemical impedance spectroscopy (EIS). The EIS experimental results were fitted to equivalent electrical circuits and the parameters corresponding to ohmic resistances, charge transfer, and diffusional processes were determined. An increase in the resulting time constants and ohmic resistance was depicted because of the degradation.After a straightforward treatment rinsing the assembly with a 1 mol/L H2SO4 solution, the MEA partially regained its initial performance, depicting a degradation rate six times slower than one observed before regeneration in acidic media. This point suggests that the temporary decline in performance of the MEA is primarily due to reversible contamination.