The Role of Gas Diffusion Layer in Cationic Contamination and Mitigation in Polymer Electrolyte Fuel Cells

To understand the role of the gas diffusion layer (GDL) in cation contamination, three methods were used to soak the PEFC MEA with a cationic solution, with the major difference being whether the CCM was completely/partially exposed to the cationic solution or separated by the GDL and gasket. Significant performance drop was observed with the CCMs which were in direct/partially contact with the Ca 2+ solution, and no significant change in performance occurred where the CCM was separated by the GDL and gasket. It seems that the GDL acts as a barrier to the transport of Ca +2 into the CCM, possibly due to very highly hydrophobic nature of the GDL. When a surfactant was added to the cationic solution to increase the wettability of the GDL, a drop in the performance was observed which verified that the hydrophobic GDL hindered the transport of Ca 2+ into the CCM. When the CCM was reprotonated, the performance was almost fully recovered.