Effect of low anode catalyst loadings on automotive PEM fuel cell start/stop durability

Start/stop degradation of proton exchange membrane (PEM) fuel cell systems is one of the major contributors for stack voltage degradation in automotive applications. In this paper, the effect of low anode catalyst loadings on automotive PEM fuel cell start/stop durability was studied. Membrane electrode assemblies (MEAs) with three different anode catalyst loadings were investigated by simulated start/stop tests using a 50 cm2 single cell. It was found that a decrease of anode catalyst loading from 0.4 mg/cm2 to 0.05 mg/cm2 improves start/stop voltage degradation by a factor of 1.8 without compromising fuel cell performance. This improved start/stop durability is consistent with kinetic model predictions based on the lowered oxygen reduction kinetics on low-loaded anode electrodes. This work demonstrates that the lower the oxygen reduction kinetics of the anode catalyst, the less the start/stop voltage degradation.