Metal oxide complexes as precursors of sulfide catalysts for HDS of DBT

Abstract

Metal oxide complexes based on Ni, Co, Mo, or W were prepared by a hydrothermal method and layered structures, identified by X-ray diffraction (XRD), were obtained. Subsequently, layered materials were thermally treated with air and H₂S/H₂ to obtain transition metal sulfide phases. The physicochemical properties of the materials were also determined by chemical analysis by atomic absorption (AA), thermogravimetric (TGA) and differential (DTA) analyses, hydrogen temperature-programmed reduction (H₂-TPR), X-ray photoelectron spectroscopy (XPS), BET surface area measured by nitrogen physisorption, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). All catalysts were tested in the hydrodesulfurization (HDS) reaction of dibenzothiophene (DBT) at 593 K and 5.5 MPa. The results indicated that the activity of the catalysts is hexavalent metal (Mo and W) dependent. The NiCoMoS catalyst showed the highest activity with a DBT conversion of 96%.