High-Entropy Modulated High-Spin Localized Cobalt Sites Enhance Catalytic Ozonation for Efficient Odor Control

Abstract

Catalytic ozonation technology is crucial for environmental remediation due to its exceptional efficiency and capability for complete mineralization of organic pollutants. However, hindered by spin-forbidden transitions, effective catalytic ozonation remains contingent upon the electronic properties and interfacial interactions of the catalyst. Recent studies identify interfacial atomic metal-oxygen species (*O) as a key descriptor in catalytic ozonation, determining the derivation of reactive species and subsEquationuent reactivity. Herein, we modulated the high-spin localized Co active sites in HE-Co₃O₄ via a high-entropy strategy, which selectively stabilizes *O surface species, thereby enhancing catalytic ozonation efficiency. HE-Co₃O₄ exhibits a five-fold higher degradation rate than Co₃O₄ for 50 ppm CH₃SH elimination (63-fold the mass activity compared to commercial MnO₂) while maintaining exceptional stability over 24 h at 298 K. Electron paramagnetic resonance (EPR) and magnetization hysteresis (M-H) measurements confirm the transition of Co³⁺ to high-spin states in HE-Co₃O₄. Density functional theory (DFT) calculations reveal that unpaired electrons enhance the hybridization of Co 3d with O 2p orbitals, thereby establishing a *O-mediated interfacial pathway. This mechanism is directly observed through in situ Raman spectroscopy. These findings provide insights into the targeted modulation of catalyst electronic structures for ozone-catalyzed environmental remediation.