High-temperature polymer electrolyte fuel cell using poly(vinylphosphonic acid) as an electrolyte shows a remarkable durability

The development of a high-performance, durable, and less expensive membrane electrode assembly (MEA) composed of a polymer electrolyte membrane and electrocatalysts is important for developing fuel cells. Herein, we described the design and fabrication of an electrocatalyst with carbon black, polybenzimidazole doped with poly(vinylphosphonic acid) (PVPA), and platinum nanoparticles as an electron-conducting support material, an electrolyte, and a metal catalyst, respectively. Most importantly, we used PVPA in place of phosphoric acid, which is a widely used acid dopant, as the acid dopant for both the electrocatalyst and the polymer electrolyte membrane. We reported that the use of PVPA is crucial for the high performance of the MEA because it prevented the leaching of acid molecules from the MEA, which led to high durability compared to that of the phosphoric acid-doped MEAs. Here come the polymers in black: A new electrocatalyst composed of platinum nanoparticles deposited homogeneously on a polybenzimidazole-wrapped carbon black is fabricated. The composite is doped with poly(vinylphosphonic acid). The use of poly(vinylphosphonic acid) in place of phosphoric acid, which is a typical acid dopant, demonstrates dramatic durability improvement in the testing of fuel cells.