Coexisting Single‐Atomic Fe and Ni Sites on Hierarchically Ordered Porous Carbon as a Highly Efficient ORR Electrocatalyst

• Published in: Advanced materials (Weinheim) 2020-10, Vol.32 (42), p.e2004670-n/a
• Main Authors: Zhu, Zhengju, Yin, Huajie, Wang, Yun, Chuang, Cheng‐Hao, Xing, Lei, Dong, Mengyang, Lu, Ying‐Rui, Casillas‐Garcia, Gilberto, Zheng, Yonglong, Chen, Shan, Dou, Yuhai, Liu, Porun, Cheng, Qilin, Zhao, Huijun
• Format: Article
• Language: English
• Subjects: Carbon; electrocatalysis; Electrocatalysts; Fine structure; fuel cell; Fuel cells; hierarchically porous structure; Iron; Materials science; Nickel; oxygen reduction reaction; Oxygen reduction reactions; single atom catalyst
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202004670

The development of oxygen reduction reaction (ORR) electrocatalysts based on earth‐abundant nonprecious materials is critically important for sustainable large‐scale applications of fuel cells and metal–air batteries. Herein, a hetero‐single‐atom (h‐SA) ORR electrocatalyst is presented, which has atomically dispersed Fe and Ni coanchored to a microsized nitrogen‐doped graphitic carbon support with unique trimodal‐porous structure configured by highly ordered macropores interconnected through mesopores. Extended X‐ray absorption fine structure spectra confirm that Fe‐ and Ni‐SAs are affixed to the carbon support via FeN4 and NiN4 coordination bonds. The resultant Fe/Ni h‐SA electrocatalyst exhibits an outstanding ORR activity, outperforming SA electrocatalysts with only Fe‐ or Ni‐SAs, and the benchmark Pt/C. The obtained experimental results indicate that the achieved outstanding ORR performance results from the synergetic enhancement induced by the coexisting FeN4 and NiN4 sites, and the superior mass‐transfer capability promoted by the trimodal‐porous‐structured carbon support. A hetero‐single‐atom oxygen reduction reaction (ORR) electrocatalyst is presented, which has atomically dispersed Fe and Ni coanchored to a microsized nitrogen‐doped carbon support with unique trimodal‐porous structure configured by ordered macropores interconnected through mesopores. The achieved outstanding ORR performance results from the synergetic enhancement induced by the coexisting FeN4 and NiN4 sites, and the superior mass‐transfer capability.