https://scholars.lib.ntu.edu.tw/handle/123456789/575819
標題: | Tuning the Coordination Environment in Single-Atom Catalysts to Achieve Highly Efficient Oxygen Reduction Reactions | 作者: | CHIH-JUNG CHEN RU-SHI LIU |
關鍵字: | Atoms; Catalyst activity; Coordination reactions; Density functional theory; Design for testability; Electrolytic reduction; Energy conversion; Metal ions; Metals; Nickel compounds; Oxygen; Catalytic performance; Coordination environment; Electrocatalytic activity; Electrochemical performance; Lower energy barriers; Oxygen reduction reaction; Single metal atoms; Structural differences; Iron compounds; carbon; cobalt; iron; metal; metal ion; nickel; nitrogen; phosphorus; phthalocyanine; sulfur; Article; catalyst; chemical bond; chemical structure; density functional theory; electrochemical analysis; energy conversion; oxygen reduction reaction; reduction (chemistry); structure analysis; synthesis; X ray absorption spectroscopy | 公開日期: | 2019 | 卷: | 141 | 期: | 51 | 起(迄)頁: | 20118-20126 | 來源出版物: | Journal of the American Chemical Society | 摘要: | Designing atomically dispersed metal catalysts for oxygen reduction reaction (ORR) is a promising approach to achieve efficient energy conversion. Herein, we develop a template-assisted method to synthesize a series of single metal atoms anchored on porous N,S-codoped carbon (NSC) matrix as highly efficient ORR catalysts to investigate the correlation between the structure and their catalytic performance. The structure analysis indicates that an identical synthesis method results in distinguished structural differences between Fe-centered single-atom catalyst (Fe-SAs/NSC) and Co-centered/Ni-centered single-atom catalysts (Co-SAs/NSC and Ni-SAs/NSC) because of the different trends of each metal ion in forming a complex with the N,S-containing precursor during the initial synthesis process. The Fe-SAs/NSC mainly consists of a well-dispersed FeN4S2 center site where S atoms form bonds with the N atoms. The S atoms in Co-SAs/NSC and Ni-SAs/NSC, on the other hand, form metal-S bonds, resulting in CoN3S1 and NiN3S1 center sites. Density functional theory (DFT) reveals that the FeN4S2 center site is more active than the CoN3S1 and NiN3S1 sites, due to the higher charge density, lower energy barriers of the intermediates, and products involved. The experimental results indicate that all three single-atom catalysts could contribute high ORR electrochemical performances, while Fe-SAs/NSC exhibits the highest of all, which is even better than commercial Pt/C. Furthermore, Fe-SAs/NSC also displays high methanol tolerance as compared to commercial Pt/C and high stability up to 5000 cycles. This work provides insights into the rational design of the definitive structure of single-atom catalysts with tunable electrocatalytic activities for efficient energy conversion. ? 2019 American Chemical Society. |
URI: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-85076973914&doi=10.1021%2fjacs.9b09352&partnerID=40&md5=ab89f39967b059c16eca1df52152a8d7 https://scholars.lib.ntu.edu.tw/handle/123456789/575819 |
ISSN: | 27863 | DOI: | 10.1021/jacs.9b09352 |
顯示於: | 化學系 |
在 IR 系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。