“…Proton exchange membrane fuel cells (PEMFCs) have been widely investigated as one of the alternatives to fossil energy in the past decades due to their eco-friendly nature, high energy conversion efficiency, low thermal radiation, and high power output [ 1 , 2 , 3 ]. Particularly, high-temperature PEMFCs (HT−PEMFCs), which operate above 100 °C, exhibit advantages including improved carbon monoxide tolerance, increased electrode reaction kinetics, and simplified hydrothermal management [ 4 , 5 , 6 ]. However, the perfluorinated sulfonic acid membrane represented by Nafion cannot meet the requirements of an HT−PEMFC due to its dramatically reduced conductivity caused by severe water loss above 100 °C [ 7 , 8 , 9 ].…”