Effect of Chloride on PEFCs in Presence of Various Cations

Abstract

The performance and durability of Polymer electrolyte fuel cells (PEFCs) were investigated by separately introducing HCl and five different chloride salts (AlCl3, FeCl3, CrCl3, NiCl2, and MgCl2) into the air stream of an operating fuel cell. Under the same operating conditions and at a fixed chloride (Cl−) concentration of 50 ppm in air stream, it appeared that HCl affected the cell performance faster than the other chloride salts, therefore the presence of the cation in the contaminant solutions slowed and/or reduced the decrease in the cell performance. The overall cell performance degradation was ranked as HCl, AlCl3 > FeCl3 > CrCl3 > NiCl2, MgCl2. The performance degradation is believed to be due to the adsorption of chloride on the Pt surface reducing active surface area. At lower relative humidity, the contaminant concentration increased in liquid phase and salt precipitated eventually blocking some of the flow channels and the GDL surface and resulted in even lower cell performance.