Mitigating CS2 poisoning in PEM fuel cells: ORR suppression effects, MEA recovery and protection strategies

Proton exchange membrane fuel cells (PEMFCs) have achieved significant commercial deployment due to their high power density, rapid start-up capability, and compatibility with a wide range of applications. However, PEMFC performance can be highly sensitive to gaseous impurities in industrial environments, particularly sulfur-containing species that poison Pt-based catalysts. In this work, the impact of carbon disulfide (CS 2 ) exposure on PEMFC performance is systematically investigated at both the catalyst and membrane electrode assembly (MEA) levels. It is shown that CS 2 suppresses Pt/C oxygen reduction reaction activity by reducing the electrochemically active surface area and changing the reaction pathway from the four-electron to the two-electron reaction pathway. Performance recovery strategies are examined in both half-cell and single-cell configurations – where the best approach allows more than 99% of the performance to be recovered. Lastly, it is demonstrated that CS 2 poisoning can be effectively prevented through air filtration using a commercial filter. These results provide new insights into CS 2 -induced PEMFC degradation and practical guidance for recovery and protection under realistic airborne contamination conditions.