Influence of CO concentration and reactant gas pressure on cell performance in PAFC

The effects of CO concentration and reactant gas pressure on cell performan ce in phosphoric acid fuel cell have been studied by measuring current-volt age characteristics and by using ac impedance technique. The single cells w ere tested as a function of CO concentration of 0-0.986 vol% in fuel gas an d of reactant gas pressure of 0-4 atm in the range of temperature of 160-22 0 degreesC. The presence of CO has significant effect on the electrode inte rfacial resistance above 0.721 vol% CO due to CO adsorption. These results were discussed as related to electrode reaction kinetics. In the pressurize d cell. both internal resistance and electrode impedance of the cell decrea sed with increasing gas pressure, which are considered to increase the cell performance. (C) 2001 Published by Elsevier Science Ltd on behalf of the I nternational Association for Hydrogen Energy.