Versatile pathways for oxidating organics via peroxymonosulfate activation by different single atom catalysts confining with Fe–N4 or Cu–N4 sites

Herein, we prepared two kinds of single-atom catalysts (SACs) with uniformed coordination structures (M−N 4 , M = Fe, and Cu) for evaluating the versatile pathways of peroxymonosulfate (PMS) activation by different metal sites. Fe-SAC exhibited a higher catalytic performance than that of Cu-SAC for chloroquine phosphate (CQP) oxidation. Results showed that the high-valent iron-oxo species accounted for 74.5 % for CQP oxidation in Fe-SAC/PMS system, while radicals (SO 4 •– and HO • ) dominated the CQP oxidation (58.3 %) in Cu-SAC/PMS system, which was associated to the different spin-state of the metal sites for PMS adsorption and breakage of O O in PMS as well as the intermediates in versatile pathways. The SACs were then fixed onto the catalytic filter for PMS activation , which showed stable and effective catalytic performance for versatile recalcitrant organics. Overall, this work not only provided the atomic-level knowledge on PMS activation, but also gave the potential applications of Fenton-like for water remediation.