Theoretical study of local S coordination environment on Fe single atoms for peroxymonosulfate-based advanced oxidation processes

Tuning the electronic structure of single atom catalysts (SACs) is an effective strategy to promote the catalytic activity in peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs). Herein, a series of Fe-based SACs with S1/2/3/4-coordination numbers on graphene were designed to regulate the electronic structural of SACs at molecular level, and their effects on PMS activation were investigated via density function theory (DFT). The calculation results demonstrate that the electron structure of the active center can be adjusted by coordi-nation environment, which further affects the activation of PMS. Among the studied Fe-SX-C4_X catalysts, with the increase of the S coordination number, the electron density of the Fe-SX-C4_X active center was optimized. The active center of the Fe-S4-C0 catalyst has a largest positive charge density, exhibiting the highest number of electron transfer. It also has a lower kinetic energy barrier (0.28 eV) for PMS dissociation. Organic pollutant such as bisphenol A (BPA) can achieve stable adsorption on Fe-SX-C4_X catalysts, which is conducive to subsequent

Automated summary

Tuning the electronic structure of Fe-based single atom catalysts on graphene can optimize the activation of peroxymonosulfate (PMS) in advanced oxidation processes (AOPs). Through density function theory (DFT) calculations, it was found that the coordination environment can adjust the electron structure of the active center, affecting the PMS activation. Fe-S4-C0 catalyst with higher S coordination number showed the highest positive charge density, most electron transfer, and lower kinetic energy barrier for PMS dissociation. Fe-SX-C4_X catalysts can stably adsorb organic pollutants like bisphenol A (BPA), facilitating subsequent reactions.