Enhancing ¹O₂ Generation Performance by Regulating C and N Coordination for Efficient Fenton-Like Catalytic Process

Area of Science:

• Catalysis
• Environmental Chemistry
• Materials Science

Background:

• Singlet oxygen (¹O₂) is crucial for selective organic pollutant degradation via Fenton-like reactions.
• Understanding the structure-activity relationship of single-atom catalysts (SACs) is key for efficient ¹O₂ generation.
• Iron SACs with varying coordination environments are explored for modulating ¹O₂ production.

Purpose of the Study:

• To investigate how coordination configurations of iron SACs influence the selective generation of ¹O₂.
• To enhance Fenton-like reaction activity for organic pollutant degradation by optimizing catalyst structure.
• To establish structure-activity trends for designing efficient catalysts for ¹O₂ production.

Main Methods:

• Synthesis of three iron SACs with distinct coordination environments: Fe_SAC─N₄, Fe_SAC─N₃─C₁, and Fe_SAC─N₂─C₂.
• Activation of peroxymonosulfate (PMS) to generate ¹O₂ using the synthesized catalysts.
• Density Functional Theory (DFT) calculations to elucidate reaction mechanisms and electronic properties.

Main Results:

• Replacing nitrogen with carbon atoms in the Fe coordination sphere enhances ¹O₂ selectivity and Fenton-like activity.
• Fe_SAC─N₂─C₂ exhibited optimal catalytic activity, stability, and environmental tolerance.
• ¹O₂ selectivity increased with decreasing nitrogen coordination number: Fe_SAC─N₄ (73%) < Fe_SAC─N₃─C₁ (82%) < Fe_SAC─N₂─C₂ (90%).

Conclusions:

• Decreasing nitrogen coordination in iron SACs promotes selective ¹O₂ generation and enhances catalytic performance.
• DFT calculations confirm that carbon incorporation optimizes electronic properties and lowers energy barriers for ¹O₂ production.
• This study provides a mechanistic understanding and design principles for developing SACs for selective pollutant degradation.