Carbon corrosion behaviors and the mechanical properties of proton exchange membrane fuel cell cathode catalyst layer

Carbon corrosion-induced catalyst layer destruction is the primary reason to the performance decay of proton exchange membrane fuel cells (PEMFCs). In this study, the accelerated stress test (AST) on carbon corrosion was conducted, and real-time CO₂ evolution was measured in-situ by non-dispersive infrared (NDIR) analysis. The performance degradation was investigated by the reduction of the current density and the loss of electrochemical active surface area (ECSA) of Pt. The loss of catalyst layer porosity and increase of mass transport resistance were investigated by the visible reduction of porosity and thickness in the cathode catalyst layer (CCL). Further mechanical tensile tests showed that the elastic modulus of CCL remained unchanged initially, and then increased probably due to the compaction of CCL. In the final step, it decreased due to the complete failure of the material. Thus, carbon corrosion was proved to alter the mechanical strength of CCL.