Coexisting Single-Atomic Fe and Ni Sites on Hierarchically Ordered Porous Carbon as a Highly Efficient ORR Electrocatalyst
© 2020 Wiley-VCH GmbH 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.
Zhu, Z., Yin, H., Wang, Y., Chuang, C., Xing, L., Dong, M., Lu, Y., Casillas-Garcia, G., Zheng, Y., Chen, S., Dou, Y., Liu, P., Cheng, Q. & Zhao, H. (2020). Coexisting Single-Atomic Fe and Ni Sites on Hierarchically Ordered Porous Carbon as a Highly Efficient ORR Electrocatalyst. Advanced Materials,