Asymmetrically Coordinated CoB1N3 Moieties for Selective Generation of High-Valence Co-Oxo Species via Coupled Electron-Proton Transfer in Fenton-like Reactions

High-valence metal species generated in peroxymonosulfate (PMS)-based Fenton-like processes are promising candidates for selective degradation of contaminants in water, the formation of which necessitates the cleavage of O-H and O-O bonds as well as efficient electron transfer. However, the high dissociation energy of O-H bond makes its cleavage quite challenging, largely hampering the selective generation of reactive oxygen species. Herein, an asymmetrical configuration characterized by a single cobalt atom coordinated with boron and nitrogen (CoB1N3) is established to offer a strong local electric field, upon which the cleavage of O-H bond is thermodynamically favored via a promoted coupled electron-proton transfer process, which serves an essential step to further allow O-O bond cleavage and efficient electron transfer. Accordingly, the selective formation of Co(IV)(sic)O in a single-atom Co/PMS system enables highly efficient removal performance toward various organic pollutants. The proposed strategy also holds true in other heteroatom doping systems to configure asymmetric coordination, thus paving alternative pathways for specific reactive species conversion by rationalized design of catalysts at atomic level toward environmental applications and more.

Automated summary

High-valence metal species generated in PMS-based Fenton-like processes offer selective degradation of contaminants in water, achieved by cleaving O-H and O-O bonds as well as efficient electron transfer. An asymmetrical configuration, characterized by a single cobalt atom coordinated with boron and nitrogen, facilitates the thermodynamically favorable cleavage of O-H bond, leading to the formation of Co(IV)(sic)O in a single-atom Co/PMS system and highly efficient removal of various organic pollutants. This strategy can be extended to other heteroatom doping systems, providing alternative pathways for specific reactive species conversion through atomic-level catalyst design for environmental applications.