Effects on Wetting Agents in Cationic Contamination and Mitigation in PEFCs

Abstract

A role of the gas diffusion layer (GDL) in cationic contamination and mitigation has been studied with isopropanol (IPA) as a wetting agent of the GDL. For this test, the catalyst coated membrane is not in direct contact with the contaminating solution, being separated by both the GDL and the gasket. The hydrophobic layer of the GDL acts as a barrier to the transport of foreign cations into a membrane. The effect on performance of the added 15% IPA as a wetting agent in the cationic solution was verified by an ex-situ soak method and by an in-situ injection method for both mitigation and recovery processes. Wetting forces and contact angles were measured to quantify the GDL wettability changes attributed to the added IPA solution. The cationic mitigation solution and the acid cleaning solution can transport across the GDL into the CCM, but the overall cell performance was not fully recovered.