Degradation mitigation in PEFCs using composite PEMs

The influence of inorganic additives comprising cerium oxide, manganese oxide, platinum supported cerium oxide and cerium oxide-manganese oxide composites on degradation mitigation in polymer electrolyte fuel cells is examined. The inorganic additives synthesized or modified in-house are characterized by XRD and TEM. Composite membranes prepared are tested for proton conductivity and used to manufacture membrane electrode assemblies (MEAs). The MEAs are tested to evaluate the macroscopic rate of membrane degradation as well as performance. The inorganic additives under consideration all resulted in an order of magnitude or greater reduction in the macroscopic rate of membrane degradation as estimated by the fluoride emission rate (FER), while maintaining membrane conductivities and MEA close to unmodified membranes (with the one exception being the ceria-manganese oxide composites, which demonstrated lower conductivity and MEA performance).