<p>NiMoW/Zr-SBA-15 supported catalysts have been investigated for modification of SBA-15 by using zirconia incorporation method, with variation of theoretical molar ratio Zr/Si = 0.07. The beneficial effect of EDTA insertion at neutral pH on NiMoW/Zr-SBA-15 oxide catalysts was studied by sol-gel method. EDTA was used as a chelating agent during the impregnation step with a theoretical molar ratio Ni: EDTA = 1:1 adjusting at neutral pH. Then, trimetallic catalysts were characterized at each step of the preparation (drying and calcination). X-Ray diffraction, Transmission electron microscopy and N₂ physisorption results demonstrated that the incorporation of metals did not significantly impact the mesoporous morphology, as evidenced by the persistence of the support’s characteristic reflections. Both synthesized catalysts demonstrate adsorption-desorption isotherms type IV and H1-type hysteresis characteristic of mesoporous materials with uniform morphology. The Atomic absorption spectroscopy and X-ray photoelectron spectroscopy analyses agree that the impregnation of the metallic phases deposited on the surface of the catalysts was effective. By X-ray photoelectron spectroscopy, Raman spectroscopy, and Ultraviolet-Visible diffuse reflectance spectroscopy confirm that the addition of EDTA at neutral pH modifies the nature of the nickel, molybdenum, and tungsten oxide species. Moreover, the formation of nickel oxide species with well-defined octahedral symmetry is enhanced, and the dispersion of molybdenum and tungsten oxide species is optimized. Finally, a change in the oxidation state of the molybdenum oxide species was observed, which has the potential to contribute to more effective HDS catalytic formulations.</p> Graphical Abstract <p></p> <p>Schematic representation of the addition of ethylene diamine tetraacetic acid (EDTA) at a neutral pH, which allows for the effective dispersion of the oxide phase species of molybdenum (Mo) and tungsten (W) on the Zr-SBA-15 support.</p>