Regulating Fe-spin state by atomically dispersed Mn-N in Fe-N-C catalysts with high oxygen reduction activity
| Autor: | Hengbo Yin, Junqi Cheng, Xiaoyi Xue, Pengfei Yuan, Jiawei Zhu, Jin Li, Gege Yang, Yongfeng Hu, Jianan Zhang, Wenzheng Cheng, Bang-An Lu, Wenjing Xu, Gan Qu, Shichun Mu, Jin-Song Hu |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Spin states Energy science and technology Science Inorganic chemistry General Physics and Astronomy chemistry.chemical_element 02 engineering and technology Electron 010402 general chemistry Electrocatalyst 01 natural sciences Oxygen Article General Biochemistry Genetics and Molecular Biology Catalysis Nanoscience and technology Power density Multidisciplinary Rational design General Chemistry 021001 nanoscience & nanotechnology Antibonding molecular orbital 0104 chemical sciences Chemistry chemistry 0210 nano-technology |
| Zdroj: | Nature Communications, Vol 12, Iss 1, Pp 1-10 (2021) Nature Communications |
| ISSN: | 2041-1723 |
| Popis: | As low-cost electrocatalysts for oxygen reduction reaction applied to fuel cells and metal-air batteries, atomic-dispersed transition metal-nitrogen-carbon materials are emerging, but the genuine mechanism thereof is still arguable. Herein, by rational design and synthesis of dual-metal atomically dispersed Fe,Mn/N-C catalyst as model object, we unravel that the O2 reduction preferentially takes place on FeIII in the FeN4 /C system with intermediate spin state which possesses one eg electron (t2g4eg1) readily penetrating the antibonding π-orbital of oxygen. Both magnetic measurements and theoretical calculation reveal that the adjacent atomically dispersed Mn-N moieties can effectively activate the FeIII sites by both spin-state transition and electronic modulation, rendering the excellent ORR performances of Fe,Mn/N-C in both alkaline and acidic media (halfwave positionals are 0.928 V in 0.1 M KOH, and 0.804 V in 0.1 M HClO4), and good durability, which outperforms and has almost the same activity of commercial Pt/C, respectively. In addition, it presents a superior power density of 160.8 mW cm−2 and long-term durability in reversible zinc–air batteries. The work brings new insight into the oxygen reduction reaction process on the metal-nitrogen-carbon active sites, undoubtedly leading the exploration towards high effective low-cost non-precious catalysts. The working mechanism of several low-cost electrocatalyst materials is still arguable. Here the authors show a model Fe,Mn/N-C catalyst where the oxygen reduction preferentially takes place on Fe(III) sites with the intermediate spin state (t2g4 eg1) caused by the adjacent Mn-N moieties. |
| Databáze: | OpenAIRE |
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