Interfacial enhancement of O* protonation on Fe2N/Fe3C nanoparticles to boost oxygen reduction reaction and the fuel cell in acidic electrolyte

作者：Lv, Chunxiao; Zhu, Yukun; Zhang, Wei; Xu, Wenjia; Ren, Jun; Liu, Hongwei; Yang, Xianfeng; Cai, Rongsheng; Jin, Sun^*; Li, Daohao^*; Yang, Dongjiang

来源：Materials Today Energy, 2021, 21: 100834.

DOI：10.1016/j.mtener.2021.100834

• Alginate
• Fe2N/Fe3C interface
• Fe-based catalysts
• H-2-O-2 fuel cell

Understanding the origin of high activity of Fe-N-C electrocatalysts in oxygen reduction reaction (ORR) is critical but still challenging for developing efficient non-precious metal catalysts in fuel cells and metal-air batteries. Herein, we developed Fe-based ORR catalysts containing highly dispersed interfaces of Fe2N/Fe3C and revealed the origin of its activity by intensively investigating the structure of the catalysts and their correlations with the electrochemical performance. It was found that the Fe2N/Fe3C with a well-matched interface displays a half-wave potential of 0.764 V (vs. RHE) and high current density in acidic electrolytes. In addition, the H-2-O-2 fuel cell assembled using Fe2N/Fe3C as the cathode exhibits excellent performance with a peak power density of 713 mW/cm(-1). The experimental and computational results reveal that the interface of the Fe2N/Fe3C heterojunction is essential for the ORR in acidic electrolytes because it provides a remarkable decrease in the maximum free energy change of O* protonation to OH*.

• 单位
  青岛大学