Robust Fe-N₄-C₆O₂ single atom sites for efficient PMS activation and enhanced Fe^IV = O reactivity

Area of Science:

• Materials Science
• Catalysis
• Environmental Chemistry

Background:

• Microenvironment regulation of Fe-N4 single-atom catalysts (SACs) is crucial for peroxymonosulfate (PMS) activation.
• Conventional heteroatom substitution in primary coordination enhances activity but compromises Fe-N4 symmetry and stability.

Purpose of the Study:

• To investigate oxygen doping in the secondary coordination shell of Fe-N4 SACs to improve catalytic activity and stability.
• To resolve the inherent activity-stability trade-off in single-atom catalyst design.

Main Methods:

• Fabrication of Fe-N4-C6O2 SACs via secondary coordination engineering with oxygen doping.
• Characterization of structural and electronic properties.
• Evaluation of catalytic performance in peroxymonosulfate activation and bisphenol A degradation.

Main Results:

• Oxygen doping amplified the localized electric field while preserving Fe-N4 coordination symmetry.
• Suppressed Fe-N bond deformation, strengthening the bond and enhancing catalytic durability (>240 h).
• Increased bisphenol A degradation rate by 41.6-fold due to promoted electrophilic attack.

Conclusions:

• Secondary coordination engineering is a viable strategy to overcome the activity-stability limitations in SACs.
• Fe-N4-C6O2 SACs demonstrate enhanced performance for environmental remediation.
• This approach offers promising perspectives for designing advanced environmental catalysts.