In this manuscript, the catalytic oxidative desulfurization (CODS) process was proposed to reduce the remove the thiophene (T) and benzothiophene (BT) in diesel fuel. An organic-inorganic hybrid nanocatalyst has been synthesized using 1-Methylimidazolium (MZ) as a transfer agent, CuO nanoparticles as a support, and the highly active mono copper-substituted polyoxotungstate ([PW11CuO39], abbreviated as PW11Cu). Catalytic oxidative desulfurization involves the simultaneous use of extraction technique by an ionic liquid ([BMIM][PF6]) and catalytic oxidation by a suitable heterogeneous catalyst. The experimental condition was optimized by response surface methodology. The removal efficiency in the compounds was as follows: T < BT. In addition, the kinetic behavior of the removal of all sulfur compounds was according to a quasi-first-order model. The nanocomposite was prepared via sol-gel method and finally calcined at 400 ◦C for 4 h. The materials characterized by means of FT-IR, UV–vis, XRD, and SEM techniques. The response optimization for extractive-catalytic oxidative desulfurization was performed for the removal efficiency of T and BT. The optimum condition was determined as 14.43 min, 40.52 ◦C for reactor temperature, 86.27 mg for nanocatalyst dosage and 23.99% for oxidant concentration. According to the obtained results, the removal efficiency of thiophene and benzothiophene of diesel fuel could reach 98% and 99%, respectively. The synthesized heterogeneous nanocatalyst could be separated and recycled successfully after 5 times. This system is suggested as an effective strategy with a great potential in the preparation of clean gasoline fuel.
