Hybrid proton exchange membrane

A membrane assembly comprising:

• a proton exchange membrane for a fuel cell, said membrane having a cathode side and an anode side,
• a catalytic cathode layer, and
• a catalytic anode layer;
• wherein said proton exchange membrane comprises two layers comprising:
• (a) a conducting and self-regenerating cathodic layer that ensures a cathode surface on the cathode side of the membrane, wherein said cathodic layer comprises at least one polymer (iii) carrying SO3H functions, at least one polymer (ii) selected from the group consisting of a silicon derivative, a sulfonated fluorinated copolymer, and a sulfonated polyether, and at least one polymer (i) carrying thiol (—SH) functions;
• and
• (b) a conducting anodic layer that ensures an anode surface on the anode side of the membrane, said anodic layer comprising at least one polymer (iii′) carrying SO3H functions;
• said polymers (iii) and (iii′) being the same or different,
• wherein said polymers (i), (ii), and (iii) comprised within the cathodic layer are in a mixture or are co-polymerized;
• wherein said membrane is coated with the catalytic cathodic layer on an outer surface of the cathodic layer of the membrane, and with the catalytic anodic layer on an outer surface of the anodic layer of the membrane, and
• wherein said cathodic layer of said membrane differs at least from the conducting anodic layer in that it comprises at least one polymer (i) carrying thiol (—SH) functions.