Catalyst Durability in Low Temperature Polymer Electrolyte Fuel Cells

Durability in the context of commercial applications can be defined as the number of times that a counter is increased by 1 before a measure of performance reaches a threshold beyond which it is considered a fail. For catalysts in fuel cells the counter is often conveniently chosen to be either hours of operation or number of cycles and the performance threshold is typically some percentage of a beginning-of-life performance metric, such as specific activity or metal surface area. Degradation is the process of performance decline and this tutorial will highlight some of the current research trends in the study of degradation mechanisms and the strategies to mitigate the effect of degradation-inducing processes.

Most catalysts are multi-component systems comprising an electrically conducting support material, typically carbon black, and a catalytic material, typically platinum. Both are subject to degradation under most operating conditions, sometimes independently, but more often influenced by each other. The second half of the tutorial will present some of the recent advances in the increase of durability by varying the catalyst components.