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Atomically FeN2 moi...
Atomically FeN2 moieties dispersed on mesoporous carbon : A new atomic catalyst for efficient oxygen reduction catalysis
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Shen, Hangjia (författare)
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- Gracia-Espino, Eduardo (författare)
- Umeå universitet,Institutionen för fysik
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Ma, Jingyuan (författare)
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Tang, Haodong (författare)
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Mamat, Xamxikamar (författare)
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Wagberg, Thomas (författare)
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- Hu, Guangzhi (författare)
- Umeå universitet,Institutionen för fysik,Key Laboratory of Chemistry of Plant Resources in Arid Regions, State Key Laboratory Basis of Xinjiang Indigenous Medicinal Plants Resource Utilization, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011, China
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Guo, Shaojun (författare)
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(creator_code:org_t)
- Elsevier BV, 2017
- 2017
- Engelska.
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Ingår i: Nano Energy. - : Elsevier BV. - 2211-2855 .- 2211-3282. ; 35, s. 9-16
- Relaterad länk:
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Ämnesord
Stäng
- Earth-abundant materials with Fe-N-C centers have been identified as promising catalysts for oxygen reduction reaction (ORR), but these alternatives for Pt catalysts are usually the porphyrin-like FeN4 configuration. The density functional theory (DFT) calculations reveal that FeN2 outperforms FeN4 due to its lower interaction with *O-2 and *OH intermediates and enhanced electron transport, however, achieving an optimum design of these earth-abundant materials with the enriched FeN2 catalytic centers is still a great challenge. Here, we report an intriguing template casting strategy to introduce a mass of atomically dispersed FeN2 moieties onto the surface of N-doped ordered mesoporous carbon for boosting ORR electrocatalysis. One of unique parts herein is to pre anchor Fe precursor on the surface of template (SBA-15) during catalyst synthesis, preventing Fe from penetrating into the carbon skeleton and facilitating the removal of excessive Fe-based particles during silica elimination by HF etching, resulting in a desirable model structure comprising only highly active atomically dispersed FeN2 sites, as confirmed by high-angle annular dark field-scanning transmission electron microscopy (HAADF-STEM), extended X-ray absorption fine structure (EXAFS) and Mossbauer spectroscopy analysis. The well-defined structure prompts us to understand the nature of the catalytic active sites, and to demonstrate that the catalyst activity is linearly proportional to the concentration of FeN2 sites. The obtained atomic electrocatalyst exhibits superior electrocatalytic performance for ORR with a more positive half-wave potential than that of Pt/C catalyst. We further establish a kinetic model to predict the ORR activity of these single-atom dispersed catalysts. The present work elaborates on a profound understanding for designing low-cost, highly efficient FeN2-based electrocatalyst for boosting ORR.
Ämnesord
- NATURVETENSKAP -- Kemi -- Oorganisk kemi (hsv//swe)
- NATURAL SCIENCES -- Chemical Sciences -- Inorganic Chemistry (hsv//eng)
- NATURVETENSKAP -- Fysik -- Den kondenserade materiens fysik (hsv//swe)
- NATURAL SCIENCES -- Physical Sciences -- Condensed Matter Physics (hsv//eng)
Nyckelord
- FeN2
- Atomic dispersion
- Oxygen reduction reaction
- Kinetic model
- Nitrogen-doped carbon
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
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