https://scholars.lib.ntu.edu.tw/handle/123456789/616378
標題: | Probing the active site in single-atom oxygen reduction catalysts via operando X-ray and electrochemical spectroscopy | 作者: | Lien H.-T. Chang S.-T. Chen P.-T. Wong D.P. Chang Y.-C. Lu Y.-R. Dong C.-L. Wang C.-H. Chen K.-H. Chen L.-C. LI-CHYONG CHEN |
公開日期: | 2020 | 卷: | 11 | 期: | 1 | 來源出版物: | Nature Communications | 摘要: | Nonnoble metal catalysts are low-cost alternatives to Pt for the oxygen reduction reactions (ORRs), which have been studied for various applications in electrocatalytic systems. Among them, transition metal complexes, characterized by a redox-active single-metal-atom with biomimetic ligands, such as pyrolyzed cobalt–nitrogen–carbon (Co–Nx/C), have attracted considerable attention. Therefore, we reported the ORR mechanism of pyrolyzed Vitamin B12 using operando X-ray absorption spectroscopy coupled with electrochemical impedance spectroscopy, which enables operando monitoring of the oxygen binding site on the metal center. Our results revealed the preferential adsorption of oxygen at the Co2+ center, with end-on coordination forming a Co2+-oxo species. Furthermore, the charge transfer mechanism between the catalyst and reactant enables further Co–O species formation. These experimental findings, corroborated with first-principle calculations, provide insight into metal active-site geometry and structural evolution during ORR, which could be used for developing material design strategies for high-performance electrocatalysts for fuel cell applications. © 2020, The Author(s). |
URI: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-85089931999&doi=10.1038%2fs41467-020-17975-y&partnerID=40&md5=fcb24b388e82d2f22a875242512f1635 https://scholars.lib.ntu.edu.tw/handle/123456789/616378 |
ISSN: | 20411723 | DOI: | 10.1038/s41467-020-17975-y | SDG/關鍵字: | carbon;cobalt;nitrogen;atomic absorption spectroscopy;catalyst;cell;design;electrochemical method;fuel cell;ligand;pyrolysis;reaction kinetics;reduction;vitamin;Article;atomic force microscopy;calculation;catalyst;crystal structure;crystallization;electrochemical analysis;energy dispersive X ray spectroscopy;human;hydrogen bond;mathematical model;nonhuman;Raman spectrometry;spectroscopy;thermal analysis;thermodynamics;X ray;X ray crystallography;X ray diffraction |
顯示於: | 凝態科學研究中心 |
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