Effect of H2O2 on Nafion® properties and conductivity at fuel cell conditions

▶ This paper reports on a quantitative examination of properties and conductivities of H2O2 degraded Nafion membranes at typical PEMFC conditions. ▶ The degradation degree (defined as loss of ion-exchange capacity, weight, and fluoride content), water uptake, and conductivity of H2O2-exposed membranes were found to strongly depend on Fe content and H2O2 treatment time. ▶ SEM cross-sections showed that the degradation initially took place in the center of the membrane. ▶ FTIR analysis revealed that Nafion degradation preferentially proceeds at the sulfonic end group and at the ether linkage located in the pendant side chain and that the H-bond of water is weakened after prolonged H2O2 exposure.