Process to produce catalyst coated membranes for fuel cell applications

A process for forming a catalyst coated membrane comprising:

• (a) providing a layered sandwich comprising:
• (i) an ionomeric polymer membrane having opposite first and second surfaces,
• (ii) a first electrocatalyst layer having a first surface adhered to a first flexible substrate and a second surface abutting the first surface of the ionomeric polymer membrane, and
• (iii) a second electrocatalyst layer having a first surface adhered to a second flexible substrate and a second surface abutting the second surface of the ionomeric polymer membrane;
• (b) placing the layered sandwich of step (a) between two synchronously-driven, resilient, thermally conductive belts;
• (c) feeding the two synchronously driven resilient, thermally conductive belts and the layered sandwich into, in sequence:
• (i) a pre-heating zone that heats the layered sandwich to a temperature of at least about 90° C. for at least about 4 minutes,
• (ii) a pair of nip rollers having a resilient coating on at least one roller, which applies an average pressure of at least about 6 MPa to the layered sandwich,
• (iii) a heating zone that heats the layered sandwich to a temperature of at least about 150° C. for at least about 1 minute,
• (iv) a pair of nip rollers having a resilient coating on at least one roller, which applies an average pressure of at least about 8 MPa to the layered sandwich, and
• (v) a cooling zone at a temperature of at least 25° C. for at least 1 minute;
• (d) transferring completely the first electrocatalyst layer adhered to a first flexible substrate to the first surface of the ionomeric polymer membrane and the second electrocatalyst layer adhered to a second flexible substrate to the second surface of the ionomeric polymer membrane;
• and
• (e) forming the catalyst coated membrane.