Fuel-Cells-Etc - 5-Layer & 7-Layer Membranes

The GDL is Teflon treated to assist in pushing the product water away from the catalyst sites, and the MPL is made of carbon powder and Teflon and applied to the cloth to give a smooth surface to apply the catalyst. The microporous layer is electrically conductive while maintaining an open pore structure to allow the gases into the reaction sites and removal of the product water. For 5-layer and 7-layer MEAs, the anode and cathode catalysts are usually applied to the selected GDL and then hot pressed on the desired membrane. This setup for easier catalyst application allows for quicker MEA fabrication.