Preparation of highly dispersed desulfurization catalysts and their catalytic performance in hydrodesulfurization of dibenzothiophene

Abstract

Micro-mesoporous ZK-1 molecular sieves with different Si/Al ratios were used as supports for binary Co-Mo hydrodesulfurization (HDS) catalysts. The CoMo/ZK-1 catalysts were prepared using an over-loading impregnation method, and characterized using N2 physisorption, X-ray diffraction, temperature-programmed NH3 desorption, temperature-programmed reduction (TPR), ultraviolet-visible diffuse reflectance spectroscopy, and high-resolution transmission electron microscopy (HRTEM). The results show that the CoMo/ZK-1 catalysts have high surface areas (∼700 m2/g), large pore volumes, and hierarchical porous structures, which promote the dispersion of Co and Mo oxide phases on the ZK-1 supports. The TPR results show that the interactions between the Co and Mo oxide phases and the ZK-1 support are weaker than those in the CoMo/γ-Al2O3 catalyst. The HRTEM results show that the CoMo/ZK-1 catalysts have better MoS2 dispersion and more active edge sites. The catalysts were tested in HDS of dibenzothiophene. Under mild reaction conditions, the activity of Co and Mo sulfides supported on ZK-1 was higher than those of Co and Mo sulfides supported on ZSM-5, AlKIT-1, and γ-Al2O3.