Facilely Tuning the First-Shell Coordination Microenvironment in Iron Single-Atom for Fenton-like Chemistry toward Highly Efficient Wastewater Purification.
Environ Sci Technol
; 57(37): 14046-14057, 2023 09 19.
Article
em En
| MEDLINE
| ID: mdl-37658810
ABSTRACT
Precisely identifying the atomic structures in single-atom sites and establishing authentic structure-activity relationships for single-atom catalyst (SAC) coordination are significant challenges. Here, theoretical calculations first predicted the underlying catalytic activity of Fe-NxC4-x sites with diverse first-shell coordination environments. Substituting N with C to coordinate with the central Fe atom induces an inferior Fenton-like catalytic efficiency. Then, Fe-SACs carrying three configurations (Fe-N2C2, Fe-N3C1, and Fe-N4) fabricate facilely and demonstrate that optimized coordination environments of Fe-NxC4-x significantly promote the Fenton-like catalytic activity. Specifically, the reaction rate constant increases from 0.064 to 0.318 min-1 as the coordination number of Fe-N increases from 2 to 4, slightly influencing the nonradical reaction mechanism dominated by 1O2. In-depth theoretical calculations unveil that the modulated coordination environments of Fe-SACs from Fe-N2C2 to Fe-N4 optimize the d-band electronic structures and regulate the binding strength of peroxymonosulfate on Fe-NxC4-x sites, resulting in a reduced energy barrier and enhanced Fenton-like catalytic activity. The catalytic stability and the actual hospital sewage treatment capacity also showed strong coordination dependency. This strategy of local coordination engineering offers a vivid example of modulating SACs with well-regulated coordination environments, ultimately maximizing their catalytic efficiency.
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Base de dados:
MEDLINE
Assunto principal:
Eletrônica
/
Hospitais
Idioma:
En
Revista:
Environ Sci Technol
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
China