Volume 52

Catalyst Layer Design for High Reversal and Free Radical Tolerance Membrane Electrode Assemblies Yan Xiao, Xiangyang Zhou, Bing Li, Pingwen Ming, Cunman Zhang

Abstract

Reactive oxygen species (ROS) produced during electrochemical reactions in proton exchange membrane fuel cells (PEMFCs), combined with the occurrence of cell reversal events, can lead to the degradation of both the catalytic layer and the proton exchange membrane. These dual challenges, which can happen simultaneously, pose significant risks to the longevity of fuel cells. In this paper, we explore the impact of incorporating CexZr1-xO2 in the cathode and IrRuO2 in the anode on the electrical performance and open-circuit durability of the membrane electrode assembly. Our findings indicate that the modified membrane electrode demonstrates exceptional open-circuit durability and resistance to voltage reversal. During a 500 h open-circuit voltage (OCV) test, nearly all voltage degradation was found to be reversible. Additionally, the hydrogen infiltration current density remained low, measuring only 5-8 mA/cm², and showed minimal variation when the inlet pressures at both the anode and cathode were increased. Moreover, the enhanced membrane electrode exhibited remarkable resistance to reverse current events. The cell reversal survival time reached 742 minutes at a current density of 200 mA/cm², with only a slight reduction in voltage and maximum power density – 24 mV and 23.2 mW/cm² after the first reversal test. These results provide valuable insights for developing highly durable membrane electrodes, paving the way for advancements in fuel cell technology.

Keywords proton exchange membrane fuel cells, catalyst layers, radical quencher, CexZr1-xO2, durability