Internal Currents, CO2 Emissions and Decrease of the Pt Electrochemical Surface Area during Fuel Cell Start-Up and Shut-Down
Résumé
This work explores the links between internal currents measured during fuel cell start-up (SU) and shut-down (SD) and the CO2 emissions in the cathode exhaust gases associated with the oxidation of the electrode carbon support. The total charge exchanged between the active and passive regions of a cell appears to be a function of the common residence time of air (or nitrogen) and hydrogen in the anode compartment during SU/SD operation. Both the CO2 emissions and the charges exchanged between the active and passive regions of the cell increase with this residence time. However, the complete oxidation of carbon to CO2 does not seem to be the main contribution to the reverse currents.