XPS characterization of zirconium-promoted CoMo hydrodesulfurization catalysts

Abstract

CoMo hydrodesulfurization catalysts (HDS) supported on mixed ZrO 2-Al 2O 3 and ZrO 2-SiO 2 oxides have been prepared via a two-step impregnation using the incipient wetness method. The S BET method, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used for characterization of the samples. Increasing the ZrO 2 content decreases the surface areas and the pore volumes of supported CoMo catalysts. The effect of Zr content on the dispersion of Mo and Co species is more pronounced in the case of CoMo/ZrO 2-SiO 2 samples; a higher dispersion corresponds to a higher ZrO 2 content. The sulfidation of molybdenum forms MoS 2. A higher degree of sulfidation of molybdenum is observed for CoMo catalysts supported on ZrO 2-Al 2O 3. A comparison between surface properties and catalytic activity behaviors of CoMo catalysts in HDS of thiophene is presented.