Despite the advantages of zeolite catalysts/carriers, the small pore size of HY zeolite causes diffusion limitations especially for bulky refractory sulfur compounds in oxidative desulfurization (ODS) of fuels. To overcome this restriction, extruded HY-zeolite/Alumina composites containing both micro and meso‑pores were successfully synthesized and used as an attractive carrier for the vanadium dispersion. Insights about the interactions between zeolite and alumina and their effects on the vanadium impregnation were given implementing different analysis approaches; BET, SEM-EDX, TEM, NH3-TPD, and UV-vis. Alumina particle piling created meso‑pores in the composites providing a positive impact on the ODS of bulky dibenzothiophene (DBT). Comparing to physical mixing of the alumina and zeolite, the extrusion approach notably enhanced the weak acid sites due to the removal/distorting tetrahedrally coordinated Al from the zeolite framework. A less increase in the strong acid sites was also resulted from the reaction of Al-OH in the alumina with the free Si-OH over the zeolite. The proposed catalyst (V/HYZ-Al(alumina/zeolite ratio=50%) exhibited an excellent DBT removal so that 1000 ppmw of DBT was eliminated completely under the optimal investigated conditions (T = 50 ◦C, O/(S+N)=12 mol/mol, time=90 min, Mcatalyst/Vfuel=10 g/L). The catalyst recyclability was proved to be acceptable during four examined successive ODS cycle
