Impact of Cationic Impurities on Low-Pt Loading PEFC Cathodes

Abstract

The effect of Ca 2+ ion contamination on a low-Pt loaded PEFC cathode (0.1 mg/cm 2 ) was investigated systematically. Calcium sulfate dissolved in water was injected at the cathode of a single cell in aerosol form under a constant current (1 A/cm 2 ). For comparison, a baseline test was also performed at the same conditions with deionized water. The performance decay rate for the baseline cell was 175 µV/h, whereas the CaSO 4 injected cell declined much faster with a decay rate of 804 µV/h. Electrochemical, physical and spectroscopical studies confirm that injecting CaSO 4 at the cathode affects the catalyst layer resulting in thinning, alters the GDL as salt deposits in the pores and no effect was seen in the polymer electrolyte membrane.