Pt-based catalyst degradation in membrane electrode assemblies for polymer electrolyte membrane fuel cells

This review focuses on understanding catalyst degradation within membrane electrode assembly (MEA) of polymer electrolyte membrane fuel cells (PEMFCs). The review provides an overview of mechanisms and pathways for Pt and Pt-alloy degradation as well as associated carbon corrosion within the MEAs and explains methods for quantifying it within the PEMFC assembly. Local environment and operating conditions have a large impact on water and heat management and hence impact Pt dissolution and redeposition, as well as alloying element dissolution. Advanced operando techniques are overviewed to characterize this heterogeneous degradation of catalysts within the complex operating environment of fuel cells. Mitigation strategies are presented, focusing on catalyst design through Pt particle size and morphology optimization, interface engineering, and optimization of MEA components to improve catalyst durability and fuel cell performance. The outlook and future directions are presented at the end.