Regulating the Metal–Support Interaction: Double Jump to Reach the Efficiency Apex of the Fe–N4-Catalyzed Fenton-like Reaction

Abstract

Peroxymonosulfate (PMS)-based advanced oxidation process (AOP) is one of the promising approaches toward addressing the global concerns on the threats of the emerging organic pollutants (EOPs). While due to the lack of understanding on the structure–activity relationship, it is challenging to rationally design a highly active and durable catalyst for the selective elimination of the EOPs. Herein, by a strategy of two-stage architecture engineering, a highly active and stable single-atom Fe catalyst for efficient pollutant degradation via Fe(IV)═O oxidation is developed. The electronic property of the polymeric carbon nitride (CN) framework was, experimentally and theoretically, evidenced to impact the physiochemical properties of the single-atom Fe sites, that is, rising the C/N ratio in the CN support results in a positive shift of the valence states of single-atom Fe sites and a favorable thermodynamic process of the Fe(IV)═O formation. On the optimum catalyst, bisphenol A (BPA) with a high concentration of 91.2 ppm can be rapidly removed within 120 s in a batch reactor under mild reaction conditions; meanwhile, the catalyst exhibits a record high stability in a fixed-bed flow reactor, for example, 124 h reaction on stream with 100% BPA removal, which corresponds to a capacity of 74.4 L per gram catalyst for treating polluted water with 22.8 ppm BPA.