Pressure-driven catalyst synthesis of Co-doped Fe3C@Carbon nano-onions for efficient oxygen evolution reaction

• Published in: Applied catalysis. B, Environmental Environmental, 2020-07, Vol.268, p.1, Article 118385
• Main Authors: Xu, Shishuai, Wang, Mingzhi, Saranya, Govindarajan, Chen, Ning, Zhang, Lili, He, Yan, Wu, Lailei, Gong, Yutong, Yao, Zhiqiang, Wang, Gongkai, Wang, Zhibin, Zhao, Shijing, Tang, Hu, Chen, Mingyang, Gou, Huiyang
• Format: Article
• Language: English
• Subjects: Bimetals; Carbon; Catalysts; Cementite; Chemical synthesis; Co-doped Fe3C@ carbon nano-onions; Cobalt; Density functional theory; Electrocatalysis; Energy technology; Face centered cubic lattice; High pressure synthesis; Iron carbides; Manganese; Nickel; Optimization; Oxygen evolution reaction; Oxygen evolution reactions; Renewable energy technologies; Synergistic effect; Transition metals; Water splitting
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2019.118385

[Display omitted] •The high pressure method is performed for rapid synthesizing iron carbides catalysts.•3d-metals (Mn/Co/Ni) are selected to optimize Fe3C@CNOs catalytic performance.•Core-shell structure Co-doped Fe3C@CNOs exhibits an excellent OER and stability.•The surface Co sites lower FCC@CNOs kinetic barrier accounting for improved OER. Optimization of electrocatalytic performance and identification of active sites for water splitting catalysts are important for the renewable energy technologies. Using one-step facile high-pressure annealing approach, herein, we report the rapid synthesis and preferred selections of 3d transition metals M (Mn, Co, and Ni)-doped Fe3C@carbon nano-onions22M-doped Fe3C@carbon nano-onions (Mn, Co, and Ni) are abbreviated as FMC@CNOs, FCC@CNOs and FNC@CNOs. for optimized electrocatalytic performance. The as-prepared highly crystalline and spheroidal core-shell-like FCC@CNOs exhibits an excellent OER activity with overpotential of 271 mV at 10 mA cm−2 among carbides catalysts, and long-term stability over 40 h (100 mA cm−2). Both experimental and density functional theory results support that the synergistic interaction of Fe and Co atom promotes FCC@CNOs having lower OER kinetic barrier and surface Co sites are activated for improved performance, not a conventional additive effect of bimetallic Co and Fe atoms. The present study provides the insights on the direct understanding of the synergistic effect of bimetallic electrocatalyts and identification of real active sites.