A novel method for preparing an active nickel phosphide catalyst for HDS of dibenzothiophene

• DOI: 10.1016/j.jcat.2009.02.013
• Publication Date: 2009-02-27T09:12:02Z
• Authors: J.A. Cecilia; A. Infantes-Molina; E. Rodríguez-Cast...; A. Jiménez-López
• Keywords: Dibenzothiophene; Phosphide; Temperature-programmed reduction

Abstract Ni 2 P catalysts supported on mesoporous silica (MCM-41) were prepared by temperature programmed reduction through a novel method using nickel(II) dihydrogenphosphite, Ni(HPO 3 H) 2 , as a precursor salt, and preparing three catalysts with nickel loadings of 5, 10 and 15 wt% denoted as Ni 2 P- x , where x is the percentage in weight of nickel. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and N 2 adsorption–desorption isotherms were used to study the formation of the phase. The dibenzothiophene (DBT) hydrodesulfurization (HDS) activity was measured for Ni 2 P- x catalysts and they showed good TOF values at 400 °C. The conversion hardly changes with the metallic loading, and increases with temperature in all cases. On the other hand, Ni 2 P-5 catalyst shows a better intrinsic activity of Ni 2 P phase. Further, an improvement in the activity is found with time on stream, where an increase in both stability and activity are observed, reaching conversions of close to 95%. XRD and XPS analysis of spent catalysts show that the formation of a more active Ni 2 P phase takes place under the reaction conditions. The support impregnated with nickel(II) dihydrogenphosphite, without prior reduction, was also active in this reaction, increasing in activity with time on stream as a consequence of the formation of the corresponding Ni 2 P or other mixed NiP x S y phases under the experimental conditions.