Modeling the Spatial and Temporal Distribution of Current in a Carbon Monoxide Poisoned Polymer Electrolyte Fuel Cell Using a Dynamic Pseudo 1-D Approach

Abstract

© The Author(s) 2019. A zero-dimensional segmented model is developed to predict the spatial and temporal behavior of the current in a polymer electrolyte fuel cell when carbon monoxide (CO) is introduced into the fuel stream. The calculated results are consistent with previous experimental observations that CO poisoning occurs first on the anode region close to the inlet. In the potentiostatic mode, this leads to a sequential drop of the segment currents. The steady state current in the segments near the inlet are generally lower than those near the outlet when the anode potential rises high enough to remove CO by electro-oxidation and reduce its concentration in the fuel stream. The situation when the cell is operated in the galvanostatic mode is more complex. As the segments near the inlet become poisoned and the segment currents drop, the current in the other segments must increase to maintain constant cell current. However, the reverse trend occurs as subsequent segments experience CO poisoning, forcing the local current at the first segments to increase even beyond their initial CO-free current density. A comprehensive assessment of the effects of CO concentration, current density, fuel stoichiometry and temperature on the segment currents in the galvanostatic mode is provided.