Almost 100 % electron transfer regime over Fe-Co dual-atom catalyst toward pollutants removal: Regulation of peroxymonosulfate adsorption mode

Fe-Co dual-atom catalyst (FeCo-DAC) with FeCo-N-6 moiety anchored in the carbon skeleton is fabricated to achieve a nearly 100 % electron-transfer process (ETP) for high-efficient peroxymonosulfate (PMS) activation by regulating PMS adsorption mode. The introduction of the adjacent metal site markedly boosted the reaction kinetic of bisphenol A removal by 5-10 times. The Fe-Co dual-site optimized the adsorption mode of PMS, in which electron rearrangement of the adsorbed PMS* complex is enhanced with weak stretching of O O bond, thus driving an exclusive selectivity for ETP pathway, as demonstrated via experiments and density functional theory (DFT) calculations. Moreover, ca. 75 % total organic carbon removal efficiency is achieved for the actual airport wastewater and the biodegradability (BOD5/COD) is greatly improved from 0.13 mg/L to 0.3 mg/L. This work provides new inspiration for the construction of Fenton-like catalysts with 100 % ETP pathway from the perspective of finely regulating the PMS adsorption mode on catalyst.