ZIF67@MFC-Derived Co/N-C@CNFs Interconnected Frameworks with Graphitic Carbon-Encapsulated Co Nanoparticles as Highly Stable and Efficient Electrocatalysts for Oxygen Reduction Reactions

• Published in: ACS applied materials & interfaces Vol. 12; no. 37; pp. 41580 - 41589
• Main Authors: Meng, Hongjie, Liu, Yiming, Liu, Haoran, Pei, Supeng, Yuan, Xianxia, Li, Hong, Zhang, Yongming
• Format: Journal Article
• Language: English
• Published: American Chemical Society 16.09.2020
• Subjects: Energy, Environmental, and Catalysis Applications; graphitic carbon; N-codoped catalyst; Co; oxygen reduction reaction; carbon nanofibers; ZIF67; catalytic stability
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.0c12069

Development of nonprecious metal catalysts for oxygen reduction reaction (ORR) to reduce or eliminate Pt-based electrocatalysts is of great importance for fuel cells. Herein, Co/N-codoped carbon with carbon nanofiber (CNF) interconnected three-dimensional (3D) frameworks and graphitic carbon-encapsulated Co nanoparticles were designed and successfully prepared via the in situ growth of zeolitic imidazolate framework-67 (ZIF67) with biomass nano-microfibrillar cellulose (MFC) and then pyrolysis. The catalyst (Co/N-C@CNFs) exhibited outstanding long-term catalytic durability with 92.7% current retention after 70 000 s, which was much higher than that of commercial Pt/C in alkaline media. The support and connection of CNFs to Co/N-C frameworks and the protection of Co nanoparticles by graphite layers contribute to their impressive long-term catalytic stability. Meanwhile, Co/C-N@CNFs displayed excellent ORR catalytic performance (E 0 = 0.952 V vs RHE, E 1/2 = 0.852 V vs RHE, and n: 4.2) in alkaline media. This strategy provides new insights into developing advanced nonprecious metal carbon-based catalysts for ORR.