Preparation of Ni—Mo/γ-Al2O3 Catalysts by Vacuum Impregnation and Their Use for Hydrodesulfurization of Dibenzothiophene

Abstract

A dual metal Ni—Mo/γ-Al₂O₃ catalyst was prepared by saturated impregnation and H₂ reduction pretreatment on γ-Al₂O₃ support with Ni as the active component and Mo as the promoter. The support and catalysts were characterized using x-ray diffraction, hydrogen temperature-programmed reduction, and scanning electron microscopy. The catalytic properties for the reaction of dibenzothiophene (DBT) were investigated in a high-pressure reactor. The hydrodesulfurization (HDS) activity was comparable with those of advanced desulfurization catalysts FHUDS-5 and FHUDS-6. The Ni—Mo catalyst had excellent dispersion characteristics on the support. Synergism between Ni and Mo was greatest at a Ni/Mo molar ratio of 2:1. The DBT conversion on Ni—Mo/γ-Al₂O₃ catalyst reached 100% at a reaction temperature of 300°C, pressure of 4 MPa, and reaction time of 150 min. The Ni—Mo/γ-Al₂O₃atalyst was significantly more active than the aforementioned two commercial FHUDS catalysts for HDS of DBT.