Analysis of Pt Catalyst Degradation of a PEFC Cathode by TEM Observation and Macro Model Simulation

Abstract

Pt particle size distributions at various positions in a cathode catalyst layer were evaluated by transmission electron microscopy (TEM) observation before and after a potential cycling test and by simple 1D macro model simulation to describe the degradation phenomena. Both the results showed similar tendencies: at the position near the membrane, the number of Pt particles for all sizes decreased with time; in contrast, at the position near the gas diffusion layer (GDL), the number of large Pt particles increased. The validity of this model is not verified yet because the precision of parameters is not confirmed. This model, however, can be used as a tool for deeper understanding of Pt degradation.