Effect of Carbon Dioxide and Ammonia on Polymer Electrolyte Membrane Fuel Cell Stack Performance

Proton exchange membrane fuel cell (PEMFC) performance degrades when impurities are present in the anode fuel gas, referred to as catalyst poisoning. This paper investigates the effect of carbon dioxide and ammonia as impurities in the anode gas of the PEMFC, and found that the presence of CO2decreases the performance of the fuel cell by up to 10%. The performance loss depends on the CO2concentration and the exposure time. The voltage loss is recoverable on passing pure hydrogen gas, indicating that a permanent poisoning of the catalyst layer has not taken place. Exposure of the fuel cell to ammonia beyond 20 ppm, even for a short duration, causes permanent PEMFC failure, probably due to the deterioration of the membrane.