Effect of Sulfur-Containing Compounds on Fuel Cell Performance

Abstract

The effect of sulfur-containing compounds on polymer electrolyte fuel cells (PEFC) was evaluated. The decrease in PEFC performance caused by the hydrogen sulfide contained in the hydrogen could not be recovered by the supply of pure hydrogen, but it was revealed that by holding the open circuit voltage with supplying pure hydrogen, the sulfur content poisoning the Pt catalyst disassociated as hydrogen sulfide and close to the initial performance was recovered. Holding the open circuit voltage and potential cycles with supplying neat air were also effective against the drop in performance due to the sulfur-containing compounds (sulfur dioxide, hydrogen sulfide) contained in the air, but the recovery in performance was limited. Further, it was revealed that the concentration of fluoride ions in the cathode effluent water increased after supplying sulfur-containing compounds with air. It is believed that when the air contains sulfur-containing compounds, not only are the active sites of the platinum catalyst reduced due to poisoning, but also the electrolyte membrane or ionomers simultaneously decompose and therefore an irreversible drop in performance is caused.