Selective oxidation of electron-rich pollutants in peroxymonosulfate-activated electro-Fenton system: The role of microenvironment-regulated cathode

•Selective electro-Fenton system was fabricated via cathode-mediated PMS activation.•Microenvironment regulation of atomic Fe inhibits undesirable radical pathways.•Optimal B-FeN4CA/PMS system exhibits highest 1O2 generation of 63.4 μmolL⁻¹min⁻¹.•Preferential removal of sulfonamides was achieved in different water matrices.•Pilot electrochemical device was used to assess the performance in real-scenario. Electro-Fenton technologies driven by peroxymonosulfate (PMS) activation have been extensively explored for abatement of organic pollutants from water. Unfortunately, a great diversity of matrix components in contaminated water scenarios inevitably and significantly compromises the efficiency of the generated radicals toward target pollutants. Thus, selective oxidation of the electro-Fenton technologies is urgently desired for cost effective and sustainable water treatment, but challenged by the traditional electron transfer pathway from cathode to PMS to mainly form SO4•− and HO• radicals. In this study, we successfully realized selective generation of 1O2, a non-radical species specific for electron-rich pollutants, by regulating the second-shell coordination environment of single-atom Fe in carbonaceous cathode. The doped electron-accepting B drives directional electron transfer from PMS to electrode and inhibiting the undesirable radical pathways. Besides, the electrochemical reduction of H+ in-situ generated from the dissociation of H-O in PMS is favourable for the formation of 1O2 as high as 163.4 μmol.L−1min−1. Fast and preferential removal of sulfonamides pollutants in different water matrices demonstrated the excellent matrix tolerance of the newly developed electro-Fenton process. A pilot electrochemical device was designed to further selective remove phenols in real-scenario application. No residual phenol was detected (