PEMFC Catalyst Layer Degradation at Intermediate Temperatures (80°C, 100°C, and 120°C)

Abstract

A growing interest in operating proton exchange membrane fuel cells at intermediate temperatures (80°C–120°C) has emerged due to the aim of implementing fuel cells in demanding applications like aviation and heavy-duty automotive uses. Operating at intermediate temperatures has several advantages, such as reduced cooling demand and increased kinetics. This is particularly important for applications that frequently experience high-load conditions, where power usage and heat production are high. However, the impact of these temperatures on the degradation of membrane electrode assemblies (MEAs) is not well understood. Here, we show performance degradation of four automotive type MEAs at 80°C, 100°C, and 120°C, studied using electrochemical characterization and electron microscopy. Higher operating temperatures leads to increased performance degradation, increased Pt growth and larger electrochemical surface area (ECSA) losses for all samples. However, neither ECSA losses nor increased resistance are sufficient to explain the severe performance loss observed for most samples at 120°C. These results highlight the importance of optimizing catalyst layers for specific operation conditions and show that the cathodic catalyst layer has a large impact on the increased degradation at intermediate-temperature operation. This study helps to understand the effects of intermediate temperature operation on the catalyst layer.