CO pre-adsorption regulated phosphoric acid redistribution for enhanced performance of high-temperature proton exchange membrane fuel cells

High-temperature polymer electrolyte membrane fuel cells (HT-PEMFCs) are considered substantial energy security tools in heavy-duty and aviation fields. Here, we discovered that the pre-adsorption of carbon monoxide (CO) on the Pt surface could regulate the phosphoric acid (PA) redistribution, which significantly enhances the intrinsic activity expression of catalysts. Through CO pre-adsorption regulation, excessive PA was prevented from occupying those Pt sites, which act as more exposed active sites available for electrocatalytic reaction. Experiment results indicate that the specific surface area of the membrane electrode assembly greatly increased with CO adsorption before the electrocatalytic reaction test. The assembled HT-PEMFCs exhibit a power density of 1054 mW cm−2 with pretty low Pt loading (0.1 mgPt cm−2 for both the anode and cathode) with this method, surpassing the performance of conventional test cases. This work presents a novel approach for reducing Pt usage while enhancing fuel cell performance.