<p>A magnetic polyoxometalate-based ionic liquid catalyst, [OMIM]₃PMo₁₂O₄₀/γ-Fe₂O₃@SiO₂@ZIF-8, was synthesized via a hierarchical core–shell approach and applied in the oxidative desulfurization (ODS) of model oil. Characterization by XRD, FT-IR, SEM-EDS, XPS, and VSM confirmed the immobilization of active species and superparamagnetic properties, facilitating magnetic recovery. Under optimized conditions (50&#xa0;mg catalyst, 0.5 mL ACN, 50&#xa0;°C, H₂O₂/sulfur molar ratio = 8), 95.48% sulfur removal from dibenzothiophene (DBT, 500 ppm) was achieved within 180&#xa0;min, with good activity toward 4,6-dimethyldibenzothiophene (4,6-DMDBT). Radical quenching experiments indicated that hydroxyl radicals (•OH) were the dominant reactive species. The catalyst maintained good activity over five cycles with only a slight decline in performance. This work provides an effective strategy for designing multifunctional polyoxometalate ionic liquid catalysts with improved mass transfer, catalytic efficiency, and recyclability for deep oxidative desulfurization.</p> Graphical Abstract <p></p>