Gas chromatography Study of Reactions of Carbon Monoxide at Different Operating Temperatures within a PEMFC

摘要

Carbon monoxide (CO) is a common impurity in hydrogen fuel that significantly affects fuel cell performance. Most studies and performance models conducted with CO to date were conducted with concentrations and catalyst loadings much higher than those anticipated in working devices and at ideal operating conditions. This work used gas chromatography to study the reaction of carbon monoxide at a trace concentration of 1 part per million with oxygen and water in a proton exchange membrane fuel cell operated at temperatures of 10 and 80 °C and an anode catalyst loading of 0.1 mg Pt cm~(-2) . CO was found to enhance a carbon corrosion reaction that showed a strong thermal dependence over the temperatures tested. CO readily reacted with oxygen at 80 °C while virtually no conversion to CO_2 was observed at 10 °C. The water gas shift reaction appeared to have been enhanced via electrochemical promotion since nearly 100 % conversion of CO was observed at both temperatures despite being kinetically limited at the temperatures used in this work. Potential oscillations were also observed for the first time for a cell with a Pt/C catalyst.