This work describes the synthesis of catalysts based on red mud/polyethylene terephthalate(PET) composites and their subsequent heat treatment under N2 atmosphere.The materials were characterized by scanning electron microscopy(SEM),temperature programmed reduction(TPR),Fourier transform infrared spectroscopy(FT–IR),X-ray diffraction(XRD),thermogravimetric(TG) analysis and N2adsorption/desorption.The catalysts were evaluated in the oxidative desulfurization reaction of dibenzothiophene(DBT) in a biphasic system.The results indicated that the PET impregnation on red mud increased the affinity of the catalyst with the nonpolar phase(fuel),in which the contaminant was dissolved,allowing a higher conversion(up to 80%) and selectivity to the corresponding dibenzothiophene sulfone.The sulfone compound is more polar than DBT and diffused into the polar solvent as indicated by the data obtained via gas chromatography–mass spectrometry(GC–MS). This work describes the synthesis of catalysts based on red mud / polyethylene terephthalate (PET) composites and their subsequent heat treatment under N2 atmosphere. The materials were characterized by scanning electron microscopy (SEM), temperature programmed reduction (TPR), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric (TG) analysis and N2adsorption / desorption.Theses were evaluated in the oxidative desulfurization reaction of dibenzothiophene (DBT) in a biphasic system.The results indicated that the PET impregnation on red mud increased the affinity of the catalyst with the nonpolar phase (fuel), in which the contaminant was dissolved, allowing a higher conversion (up to 80%) and selectivity to the corresponding dibenzothiophene sulfone. sulfone compound is more polar than DBT and diffused into the polar solvent as indicated by the data obtained via gas chromatography-mass spectrometry (GC-MS).