A potential well effect for efficient oxygen reduction and corrosion resistance under the operating temperature conditions of PEMFCs

Abstract

In recent years, fluorine-doped carbon (F–C) materials have attracted widespread attention in the oxygen reduction reaction (ORR) due to their unique performance. However, the strong electron-withdrawing nature of the F element makes metal particles not suitable for the 4e⁻ ORR in proton exchange membrane fuel cells (PEMFCs). In this work, we introduce Zn element to modulate the strong electron-withdrawing effect of F element. At the same time, utilizing the strong polarity of the C–F bond, we construct an electron confinement structure to introduce the concept of potential well in the ORR system for the first time. We prepare the PtZn i-NPs/F-CNT catalyst with a potential well effect to achieve high ORR catalytic efficiency. The catalyst exhibits good ORR performance and corrosion resistance at 80 °C. Furthermore, the PtZn i-NPs/F-CNT cathode assembly reaches a peak power density of 1.49 W cm⁻² in the H₂/O₂ environment and maintains 92.6% of the peak power density after 30 K cycles of accelerated stress testing (AST), with stable operation for 220 hours at a working voltage of 0.67 V. This study offers novel insights into developing efficient and corrosion-resistant ORR electrocatalysts for PEMFCs, serving as a foundation for future development of ORR electrocatalysts in PEMFCs.