Phosphoric acid has received the most attention as a choice of electrolyte for a high-temperature proton exchange membrane fuel cell (HT-PEMFC). Phosphoric acid has many attractive properties such as high anhydrous conductivity, good compatibility with hydrocarbon membranes, and thermal stability [1], which enables high fuel cell performance under anhydrous and elevated operating temperatures (140-180 ^oC) [2-3]. However, phosphoric acid has undesirable properties such as high catalyst poisoning, high evaporation rate at > 200 ^oC, and low acid retention from the doped membrane. Alkyl phosphonic acid may correct some of the drawbacks of phosphoric acid, improving fuel cell performance and durability.

In this presentation, we report the technical challenges and possible resolutions for HT-PEMFCs using alkyl phosphonic acid doped membranes. We focus on the effects of alkyl phosphonic acid on hydrogen oxidation and oxygen reduction reactions of Pt-based catalysts. In addition, we discuss the membrane selection of robust operation of alkyl phosphonic acid-based HT-PEMFC.

References:

[1] A.S. Lee, Y.-K. Choe, I. Matanovic, Y.S. Kim, Journal of Materials Chemistry A, 7 (2019) 9867-9876.

[2] K.H. Lim, A.S. Lee, V. Atanasov, J. Kerres, E.J. Park, S. Adhikari, S. Maurya, L.D. Manriquez, J. Jung, C. Fujimoto, I. Matanovic, J. Jankovic, Z. Hu, H. Jia, Y.S. Kim, Nature Energy, 7 (2022) 248-259.

[3] V. Atanasov, A.S. Lee, E.J. Park, S. Maurya, E.D. Baca, C. Fujimoto, M. Hibbs, I. Matanovic, J. Kerres, Y.S. Kim, Nature Materials, 20 (2021) 370-377.