Spatial proton exchange membrane fuel cell performance under carbon monoxide poisoning at a low concentration using a segmented cell system

► The impacts of CO on PEMFC were studied with a segmented cell and spatial EIS. ► The experiments were done under galvanostatic control of overall cell current. ► Injection of 2 ppm CO resulted in a voltage decrease and redistribution of segments' currents. ► Inlet segments showed a decrease in current, downstream segments exhibited an increase in current. ► An increased membrane gas crossover can mitigate the impact of CO.