A CO poisoning model for high-temperature proton exchange membrane fuel cells comprising phosphoric acid-doped polybenzimidazole membranes

We present herein a carbon monoxide (CO) poisoning model for high-temperature proton exchange membrane fuel cells (HT-PEMFCs) comprising phosphoric acid-doped polybenzimidazole membranes. In the model, the adsorption/desorption processes of CO and hydrogen on the anode Pt catalysts, and subsequent electrochemical oxidation are rigorously considered. The CO poisoning model is incorporated into a previously developed three-dimensional HT-PEMFC model, and then both numerical simulations and experimental measurements are conducted for a comparative study. The simulation results generally agree well with the experimental data under various current density conditions, highlighting that it is necessary to consider the variable hydrogen adsorption kinetics as a function of CO fractional coverage to achieve better agreement with the experimental data. Furthermore, detailed key contours for hydrogen/CO fractional coverage, anode overpotential, temperature, and current density are provided to derive greater insights into the CO poisoning mechanisms and characteristics in HT-PEMFCs.