Biomass carbonized P-V-W/C-dots/g-C₃N₄ with acid-metal synergistic catalysis and anchoring regulatory mechanism for deep oxidative desulfurization.

Conventional oxidative desulfurization (ODS) catalysts generally suffer from the problems of easy agglomeration of active components, limited electron transfer efficiency, and insufficient activation capacity. This work developed a layered composite catalyst (P-V-W/C-dots/g-C₃N₄) featuring g-C₃N₄ as the support, P-V-W as the active component, and C-dots for interfacial regulation. This biomass carbonized material was successfully synthesized by simple gradient heating and hydrothermal synthesis methods. Layered porous g-C₃N₄ as an easy-to-prepare and non-contaminating carrier for effective anchoring and spatial confinement of active components. P-V-W effectively activates H2O2 by endowing the system with an oxidatively active center through acid-metal synergistic catalysis. Meanwhile, the innovative introduction of C-dots further ensures a high degree of dispersion between the carrier and the active component, and constructs an efficient electron transfer bridge on the microscopic scale, thus facilitating rapid electron migration between multiple interfaces. Successful loading of active components, excellent dispersion state, and synergistic catalytic structure were characterized by relevant characterization tests. Desulfurization rate of 99.93 ± 0.06% can be achieved under optimal conditions (V(ILs) =0.75 mL, catalyst: model oil (0.02:5, g/mL), V(H2O2) =0.2 mL, 70 °C, 80 min). In addition, the catalyst maintained excellent desulfurization performance after 5 cycles. Combined with free radical trapping experiments (*O₂-), control experiments, kinetic analyses and EPR analyses, the oxidative desulfurization reaction mechanism can be obtained. This study achieved efficient electron transfer and active site utilization through interfacial regulation and synergistic catalysis, providing new insights for designing green sustainable eco-friendly catalysts.