Modulating Electronic Structure of Atomically Dispersed Nickel Sites through Boron and Nitrogen Dual Coordination Boosts Oxygen Reduction |
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Authors: | Fangqing Wang Rui Zhang Yangyang Zhang Ying Li Jun Zhang Wenhao Yuan Hui Liu Fei Wang Huolin L. Xin |
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Affiliation: | 1. Key Laboratory of Special Functional Materials for Ecological Environment and Information (Hebei University of Technology), Ministry of Education, Tianjin, 300130 P. R. China;2. Department of Physics and Astronomy, University of California, Irvine, CA, 92697 USA;3. School of Material Science and Engineering, Hebei University of Technology, Tianjin, 300130 P. R. China |
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Abstract: | Atomically dispersed 3D transitional metal active sites with nitrogen coordination anchored on carbon support have emerged as a kind of promising electrocatalyst toward oxygen reduction reaction (ORR) in the field of fuel cells and metal–air cells. However, it is still a challenge to accurately modulate the coordination structure of single-atom metal sites, especially first-shell coordination, as well as identify the relationship between the geometric/electronic structure and ORR performance. Herein, a carbon-supported single-atom nickel catalyst is fabricated with boron and nitrogen dual coordination (denoted as Ni-B/N-C). The hard X-ray absorption spectrum result reveals that atomically dispersed Ni active sites are coordinated with one B atom and three N atoms in the first shell (denoted as Ni-B1N3). The Ni-B/N-C catalyst exhibits a half-wave potential (E1/2) of 0.87 V versus RHE, along with a distinguished long-term durability in alkaline media, which is superior to commercial Pt/C. Density functional theory calculations indicate that the Ni-B1N3 active sites are more favorable for the adsorption of ORR intermediates relative to Ni-N4, leading to the reduction of thermodynamic barrier and the acceleration of reaction kinetics, which accounts for the increased intrinsic activity. |
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Keywords: | B, N co-doped carbon electronic structures oxygen reduction reaction single-atom catalysts |
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