Coexisting Single‐Atomic Fe and Ni Sites on Hierarchically Ordered Porous Carbon as a Highly Efficient ORR Electrocatalyst
Zhengju Zhu, Huajie Yin, Yun Wang, Cheng‐Hao Chuang, Lei Xing, Mengyang Dong, Ying‐Rui Lu, Gilberto Casillas, Yonglong Zheng, Shan Chen, Yuhai Dou, Porun Liu, Qilin Cheng, Huijun Zhao
Abstract
Abstract 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 FeN 4 and NiN 4 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 FeN 4 and NiN 4 sites, and the superior mass‐transfer capability promoted by the trimodal‐porous‐structured carbon support.