Impact of Temperature and Relative Humidity on Electrocatalyst Degradation in Polymer Electrolyte Fuel Cells: An Experimental Study

The catalyst layer, which is crucial for efficient electrochemical reactions within the PEFC, undergoes degradation. This leads to a decline in its electrochemical activity and, negatively impacting power output, durability and cost-effectiveness [1–3]. This study utilized an accelerated stress test methodology recommended by the US Department of Energy [4] to investigate the degradation mechanisms influenced by temperature and relative humidity. A single cell was subjected to controlled accelerated aging conditions simulating a realistic operating environment. The reference condition consisted of a cell temperature of 80°C and gas relative humidity of 100%. In addition to the reference condition, two other conditions were evaluated: a cell temperature of 90 °C with 100% gas relative humidity and a cell temperature of 80 °C with 50% gas relative humidity. Various electrochemical techniques, including cyclic voltammetry, polarization curves, and electrochemical impedance spectroscopy, were employed to comprehensively characterize the catalyst layer's behaviour. The experimental results demonstrated the significant influence of temperature and relative humidity on the degradation of the catalyst layer in PEFCs Figure 1 Elevated temperatures accelerated the degradation process, leading to a decrease in the electrochemically active surface area (ECSA) of the catalyst and subsequent decline in fuel cell performance. The findings emphasize the importance of managing these operating parameters to ensure the long-term stability and efficiency of PEFCs.

ACKNOWLEDGMENT
This research work is performed under the project AlpeDHues (AlpeDHues / FFG 889328) which is supported by the Austrian Research Promotion Agency (FFG).
REFERENCES
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