• 文献标题:   Incorporation of Cu-N-x cofactors into graphene encapsulated Co as biomimetic electrocatalysts for efficient oxygen reduction
  • 文献类型:   Article
  • 作  者:   YANG Y, WANG CL, GAO SQ, MAO KT, XIA GL, LIN ZY, JIANG P, HU L, CHEN QW
  • 作者关键词:  
  • 出版物名称:   NANOSCALE
  • ISSN:   2040-3364 EI 2040-3372
  • 通讯作者地址:   Univ Sci Technol China
  • 被引频次:   5
  • DOI:   10.1039/c8nr06538a
  • 出版年:   2018

▎ 摘  要

Unlike metals with incomplete d-shells such as Pt and Fe, copper (Cu) with a filled d-electron shell is generally regarded as a sluggish oxygen reduction reaction (ORR) electrocatalyst. However, laccase and other copper enzymes could catalyze the ORR efficiently in nature. Inspired by this, we incorporated Cu-N-x cofactors (Cu-N-2 and Cu-N-4) into graphene encapsulated Co frameworks by direct annealing of MOFs with a post etching process. The bioinspired electrocatalyst exhibits excellent performance and stability for ORR which is comparable to or even better than Pt/C. Meanwhile, it also illustrates a fantabulous performance in a zinc-air battery device. The excellent performance can be ascribed to the abundant atomically dispersed Cu-N-x cofactors in the graphene frameworks confirmed by aberration corrected HAADF-STEM and XAFS analyses. Density functional theory calculations suggest that when Cu atoms are coordinated with the surrounding N atoms, the valence electrons of Cu atoms will transfer to nitrogen atoms, simultaneously tuning the d electronic states near the Fermi level to realize fast ORR kinetics.