Effect of Cationic Contaminants on Polymer Electrolyte Fuel Cell Performance

Abstract

To correlate the cationic contaminant uptake of the membrane electrode assembly (MEA) with the polymer electrolyte fuel cell (PEFC) performance, MEAs were contaminated by saturating in varying concentrations of H2SO4 and Al2(SO4)3 solution to establish ex situ equilibrium cation uptake. The MEAs were then assembled and tested in a single cell hardware to determine the performance as a function of cationic contamination level. Smaller MEA coupons were also saturated at the same time as full-size MEA and were characterized to determine the cationic occupation fraction by acid site titration. It is found that the acid site occupation in the MEA increased and the cell performance decreased with increased Al ion concentration in the solution. With less than 10% occupation, the cell performance dropped from 1000 mA/cm2 to 100 mA/cm2 at 0.6 V. Upon re protonation of the MEA with H2SO4, it is found the cell performance was fully recovered.