Acta Chimica Sinica ›› 2022, Vol. 80 ›› Issue (8): 1084-1090.DOI: 10.6023/A22040143 Previous Articles     Next Articles



闫绍兵a, 焦龙a, 何传新b,*(), 江海龙a,*()   

  1. a 中国科学技术大学化学系 合肥 230026
    b 深圳大学化学系 广东深圳 518071
  • 投稿日期:2022-04-01 发布日期:2022-09-01
  • 通讯作者: 何传新, 江海龙
  • 基金资助:
    科技部重点研发计划(2021YFA1500400); 国家自然科学基金(21725101); 国家自然科学基金(22161142001); 国家自然科学基金(22001242)

Pyrolysis of ZIF-67/Graphene Composite to Co Nanoparticles Confined in N-Doped Carbon for Efficient Electrocatalytic Oxygen Reduction

Shaobing Yana, Long Jiaoa, Chuanxin Heb(), Hailong Jianga()   

  1. a Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
    b Department of Chemistry, Shenzhen University, Shenzhen, Guangdong 518071, China
  • Received:2022-04-01 Published:2022-09-01
  • Contact: Chuanxin He, Hailong Jiang
  • Supported by:
    National Key Research and Development Program of China(2021YFA1500400); National Natural Science Foundation of China(21725101); National Natural Science Foundation of China(22161142001); National Natural Science Foundation of China(22001242)

Commercial Pt/C, with the ideal 4e- transfer process for oxygen reduction reaction (ORR), is regarded as the optimal cathode catalyst of fuel cells at present. However, as a noble metal element, the high cost and scarcity of Pt seriously restrict the wide application of fuel cells. On account of this, cheap and high-performance non-noble metal catalysts receive extensive research attentions at present. In this work, by using graphene oxide (GO) as the template, we can realize the in-situ growth of Co-based metal organic framework (MOF) (ZIF-67) on the GO surface by means of the abundant oxygen-containing functional groups on GO, forming the ZIF-67/GO layered composite. During the pyrolysis at 700 ℃ in N2 atmosphere, the graphene can effectively inhibit the agglomeration of Co nanoparticles with the well retained layered morphology, which can be confirmed by scanning electron microscope (SEM) and transmission electron microscopy (TEM). The X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and nitrogen isothermal adsorption tests were used to analyze the components and microstructure of obtained materials. Moreover, the catalytic performances of different material towards ORR have been also measured by cyclic voltammetry (CV) and linear sweep voltammetry (LSV) analysis in alkaline electrolyte with rotating disk electrode (RDE) at different speeds. Thanks to the high dispersion of active sites, abundant pore structures and excellent conductivity of the obtained Co@N-C/rGO composite, it shows excellent ORR performances with an initial potential of 0.96 V and a half-wave potential of 0.83 V, far superior to that of the Co@N-C catalyst obtained by direct pyrolysis of ZIF-67, and even comparable to that of commercial Pt/C catalyst. In addition, the Co@N-C/rGO composite also exhibits good catalytic stability under constant potential for 20000 s and shows favorable methanol tolerance which is better than Pt/C, demonstrating its great potential as an oxygen reduction catalyst for fuel cell applications.

Key words: metal-organic framework, nitrogen-doped carbon, graphene, electrocatalysis, oxygen reduction reaction