Addition of dilute H2O2 solutions to H2–CO fuel gases and their influence on performance of a PEFC

Abstract

The performance of a polymer electrolyte fuel cell (PEFC) with pure H₂ and H₂–CO mixtures as fuel gases was studied at a cell temperature of 80°C using dispersed Pt as anode catalyst and Nafion^® 117 as electrolyte. The CO in the fuel gas leads to a significant loss in power density due to CO poisoning of the anode. The controlled addition of aqueous H₂O₂ solutions and the catalytic decomposition of H₂O₂ in a flow reactor at the inlet of the anode humidifier leads to a defined amount of oxygen in the fuel gas. It was shown that, with this method the same cell performance as with pure hydrogen was achieved up to CO concentrations of 500 ppm by using aqueous solutions of 5wt.% H₂O₂ .