Comparative Studies of the CoMo/MgO, CoMo/Al₂O₃ and CoMo/MgO-MgAl₂O₄ Catalysts Prepared by a Urea-Matrix Combustion Method

Abstract

Three CoMo supported catalysts with different supports, Al2O3, MgO and MgO-MgAl2O4, were prepared by a urea matrix combustion method. The physicochemical properties of the catalysts were characterized by N2 isothermal adsorption–desorption, powder X-ray diffraction (XRD) and temperature programmed reduction (TPR) techniques. The activity of these catalysts was evaluated in a fixed-bed high-pressure reactor using hydrodesulfurization of dibenzothiophene as a model reaction. The urea matrix combustion preparation method greatly favored the formation of highly dispersed Co- and Mo-oxo species on the support, which had significant influence on the hydrodesulfurization (HDS) activity. XRD analysis showed that MgO was more sensitive to the deposition of Co-O or Mo-O species than Al2O3 and MgAl2O4; the former might be potentially used as an indicator of the Co- and Mo-oxo species formation. Among these catalysts, CoMo/MgO-MgAl2O4 exhibited a high HDS activity.

Co-hydrotreatment of tire pyrolysis oil and vegetable oil for the production of transportation fuels

“…The largest surface area was observed for the fresh catalyst (234 m²/g). This surface area is similar (212 m²/g) to the one reported for a similar catalyst by Wu et al [34]. The surface area decreased for all used catalysts likely due to pore blocking.…”

Effect of urea/metal ratio on the performance of NiMoP/Al2O3 catalyst for diesel deep HDS

“…Fahai Cao et al [22][23][24][25] prepared series of TiO 2 -modified Al 2 O 3 -supported CoMo catalyst using urea matrix combustion for diesel HDS catalyst preparation, it has been found that catalyst prepared using the urea matrix combustion method had higher pore volume and surface area than those prepared by the co-impregnation and sequential impregnation methods. The UMxC method increased metal loading and avoided formation of inert phase, e.g., b-CoMoO 4 , for the HDS reaction.…”