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

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 (M‐*O) as a key descriptor in catalytic ozonation, determining the derivation of reactive species and subsequent reactivity. Herein, we modulated the high‐spin localized Co active sites in HE‐Co3O4 via a high‐entropy strategy, which selectively stabilizes Co‐*O surface species, thereby enhancing catalytic ozonation efficiency. HE‐Co3O4 exhibits a 5‐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 Co‐*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.