Controllable synthesis of nitrogen-doped carbon containing Co and Co3Fe7 nanoparticles as effective catalysts for electrochemical oxygen conversion

Xiaodong Luo; Hui Ma; Hang Ren; Xuhui Zou; Yuan Wang; Xi Li; Zhangfeng Shen; Yangang Wang; Lifeng Cui

doi:10.1016/j.jcis.2021.01.097

Controllable synthesis of nitrogen-doped carbon containing Co and Co₃Fe₇ nanoparticles as effective catalysts for electrochemical oxygen conversion

J Colloid Interface Sci. 2021 May 15:590:622-631. doi: 10.1016/j.jcis.2021.01.097. Epub 2021 Feb 2.

Authors

Xiaodong Luo¹, Hui Ma², Hang Ren², Xuhui Zou¹, Yuan Wang², Xi Li², Zhangfeng Shen³, Yangang Wang⁴, Lifeng Cui⁵

Affiliations

¹ College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing 314001, China; Department of Environmental Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
² College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing 314001, China.
³ College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing 314001, China. Electronic address: zfshen@mail.zjxu.edu.cn.
⁴ College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing 314001, China. Electronic address: ygwang8136@mail.zjxu.edu.cn.
⁵ Department of Environmental Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China. Electronic address: lifeng.cui@gmail.com.

PMID: 33582364
DOI: 10.1016/j.jcis.2021.01.097

Abstract

Sufficient and well-distributed active sites and highly conductive carbon matrix are two important factors to achieve highly efficient electrocatalysts. In this study, we report an adjusted metal-organic frameworks (MOF)-based route for the preparation of nitrogen-doped Fe/Co bimetallic electrocatalysts. With suitable Fe/Co molar ratio (Fe/Co = 1/4.15), Co nanoparticles (NPs) with mild oxidation state and Co₃Fe₇ alloys wrapped with thin graphene layers are embedded in an integrated and continuous carbon network. The corresponding FC@NCs-4.15 catalyst exhibits excellent oxygen reduction reaction (ORR) activity (onset potential (E_onset) of 0.94 V and half-wave potential (E_1/2) of 0.84 V vs RHE) in alkaline medium, close to commercial Pt/C and superior to the other two FC@NCs. The desirable ORR performance results from the uniform distribution Co₃Fe₇ active sites, electron density modification from Co NPs to surrounding carbon layers, hierarchical pore structure with large surface area, low carbon content, high pyridinic and graphitic N components. The FC@NCs-4.15 also displays satisfactory methanol crossover tolerance and durability.

Keywords: Carbon network; Co(3)Fe(7) alloys; Metal-organic frameworks; Nitrogen doping; Oxygen reduction.