Abstract: Non-proton cationic impurities are removed from the ionomer in a proton exchange membrane of an electrochemical cell and from the anode side and cathode side catalyst layers. A supply path for an anode feed to the ionomer on the anode side of the proton exchange membrane and a supply path for a cathode feed to the ionomer on the cathode side of the proton exchange membrane are provided. A regenerating fluid with acidic pH is brought into contact with the ionomer on the cathode side of the proton exchange membrane to accomplish an ion exchange of the non-proton cationic impurities with protons and thus remove the non-proton cationic impurities from the ionomer into the regenerating fluid. This removes the non-proton cationic impurities from the ionomer of the electrochemical cell without increasing the risk of corrosion and without interrupting the process of the electrochemical cell.

Abstract: Non-proton cationic impurities are removed from the ionomer in a proton exchange membrane of an electrochemical cell and from the anode side and cathode side catalyst layers. A supply path for an anode feed to the ionomer on the anode side of the proton exchange membrane and a supply path for a cathode feed to the ionomer on the cathode side of the proton exchange membrane are provided. A regenerating fluid with acidic pH is brought into contact with the ionomer on the cathode side of the proton exchange membrane to accomplish an ion exchange of the non-proton cationic impurities with protons and thus remove the non-proton cationic impurities from the ionomer into the regenerating fluid. This removes the non-proton cationic impurities from the ionomer of the electrochemical cell without increasing the risk of corrosion and without interrupting the process of the electrochemical cell.