Robust Fe-N4 center with optimized metal-support interaction for efficient pollutant degradation by Fenton-like reaction

Single-atom Fe catalysis has exhibited remarkable potentials in water treatment applications. However, rational design of single-atom Fe catalysts with controlled catalytic performance is still challenging, due to the lack of the fundamental understanding on the corelated factors of structure, property, and catalytic behavior. Herein, PMS activation performance of the single-atom Fe sites is successfully boosted by molecular-engineering on the polymeric carbon nitride (CN) framework. Benzene-1,4-diamine regulates the polymerization process, and rises the ratio of carbon/nitrogen; the valence of the single-atom Fe is thereby positively shifted, leading to favorable thermal dynamics of the high-valent Fe(IV)=O involved oxidation reaction. The carbon-rich CN supported single-atom Fe catalyst thus exhibits remarkable performance in selective degradation of a series of organic pollutants via high-valent Fe(IV)=O oxidation pathway. The findings in this work implicate the significance of electronic properties of the support as one of the essential descriptors for a robust single-atom catalyst for pollutants abatement. [Display omitted] •Benzene diamine in precursor for synthesis of single-atom Fe catalyst could positively shift the valence of Fe center.•A 5.1 times of performance improvement in bisphenol A degradation reaction was realized.•The single atom Fe catalyst with optimized valence is durable in a fixed-bed reactor.•Theoretical simulation states that positive valence of Fe center lowered the energy barrier of the catalytic reaction.