Inverted loading strategy regulates the Mn-OV-Ce sites for efficient fenton-like catalysis

Abstract

Regulating interfacial active sites to improve peroxymonosulfate (PMS) activation efficiency is a hot topic in the heterogeneous catalysis field. In this study, we develop an inverted loading strategy to engineer asymmetric Mn-O_V-Ce sites for PMS activation. Mn₃O₄@CeO₂ prepared by loading CeO₂ nanoparticles onto Mn₃O₄ nanorods exhibits the highest catalytic activity and stability, which is due to the formation of more oxygen vacancies (O_V) at the Mn-O_V-Ce sites, and the surface CeO₂ layer effectively inhibits corrosion by preventing the loss of manganese ion active species into the solution. In situ characterizations and density functional theory (DFT) studies have revealed effective bimetallic redox cycles at asymmetric Mn-O_V-Ce active sites, which promote surface charge transfer, enhance the adsorption reaction activity of active species toward pollutants, and favor PMS activation to generate (•OH, SO₄^•-, O₂^•- and ¹O₂) active species. This study provides a brand-new perspective for engineering the interfacial behavior of PMS activation.

Keywords: Asymmetric Mn–O(V)–Ce sites; DFT calculation; Electron transfer; Oxygen vacancy; PMS activation.