The performance degradation of proton exchange membrane (PEM) electrolyzers have posed a challenge for their commercial applications. Herein, the long-term performance of a PEM electrolysis cell with a sintered titanium fiber felt as porous transport layer (PTL) at anode side has been examined. The distribution of relaxation times (DRT) calculation reveals that the degradations mainly come from the increased ohmic resistance and polarization resistances related to proton transfer and charge transfer at the cathode. For the first time, Ti-ion has been found to accumulate in the cathode catalyst layer, a result of Ti-PTL corrosion at anode and subsequent Ti-ion migration under the electric field. After continuously removing the foreign ions in the water loop with ion-exchange resin, the degradation rate has decreased by 71%.

https://www.sciencedirect.com/science/article/pii/S1385894723033557