Hierarchically open-porous carbon networks enriched with exclusive Fe-Nx active sites as efficient oxygen reduction catalysts towards acidic H2-O2 PEM fuel cell and alkaline Zn-air battery

作者：Deng, Yijie; Tian, Xinlong; Chi, Bin; Wang, Qiyou; Ni, Wenpeng; Gao, Yang; Liu, Zhaoen; Luo, Junmin; Lin, Chenxiao; Ling, Liming; Cheng, Faliang^*; Zhang, Yan^*; Liao, Shijun; Zhang, Shiguo^*

来源：Chemical Engineering Journal, 2020, 390: 124479.

DOI：10.1016/j.cej.2020.124479

• Fe-N-x active sites
• Oxygen reduction catalyst
• Zn-air battery
• Fuel cell

The development of both H-2-O-2 proton exchange membrane fuel cells (PEMFCs) and Zn-air batteries are challenged by high-efficiency air cathodes with a high oxygen reduction reaction (ORR) electrocatalytic-activity. The increase of density and accessibility of active sites are widely accepted effective approach to boost the oxygen reduction reaction. In this work, we develop a template-free g-C3N4-assisted pyrolysis strategy to transform ZIF-8 polyhedrons to hierarchically open-porous carbon networks incorporated exclusive Fe-N-x active sites. Due to the integration of high specific surface area, highly open porous architecture with meso/micropores, and high-density Fe-N-x active species, the electro-catalysis performance of optimal catalysts exceed commercial Pt/C in alkaline solution, and is comparable to that of commercial Pt/C in acidic solution, which is one of the best recently reported carbon-based electrocatalysts. Impressively, when it is used as an air cathode catalyst, it achieves a high power density of 481 mW.cm(-2) in acidic H-2-O-2 proton exchange membrane fuel cell (PEMFC) and an excellent performance in the alkaline Zn-air battery (a high power density of 121 mW.cm(-2)).

• 单位
  y; 海南大学; 东莞理工学院; 西安交通大学