Synthesis and Characterization of New Substituted Sandwich-Type Polyoxometalate-Based Inorganic–Organic Hybrid Nanocomposites for Catalytic Oxidative Desulfurization of Real Gasoline

In this study, a new inorganic–organic hybrid nanocomposite (named FeW/MgO/CS) consisting of Fe-substituted sandwich-type polyoxometalate, magnesium oxide, and chitosan was synthesized and applied as a heterogeneous catalyst in catalytic oxidative desulfurization (Cat-ODS) reactions. The designed hybrid nanocomposite was fully characterized by Fourier transform infrared (FT-IR), ultraviolet–visible (UV–vis), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) techniques. The experimental results manifest that the oxidation reaction efficiencies were up to 95% for both model liquid fuels (MLFs) and gasoline under mild operating conditions. In particular, dibenzothiophene (DBTh) removal with an initial concentration of 500 ppm reached 98% after 60 min at 35 °C. The study suggested that the diffusion of sulfur-containing substrates and oxidant molecules into the channels and cavities of FeW/MgO/CS had an outstanding impact on the Cat-ODS reaction efficiency. Moreover, it is also confirmed that FeW/MgO/CS could be easily retrieved and reused several times by filtration without obvious loss of activity. Due to the high performance of FeW/MgO/CS in Cat-ODS reactions and its reusability properties, this nanocomposite can be developed for the production of clean transportation fuels.