Hydrodesulfurization of dibenzothiophene catalyzed by Ni-Mo sulfides supported on a mixture of MCM-41 and HY zeolite

Abstract

High-performance hydrodesulfurization (HDS) catalysts were prepared by supporting Ni-Mo sulfides on a mixture of mesoporous MCM-41 and microporous HY zeolite. The mixed support was obtained either by physically mixing [MCM-41-HY(M)] or by overgrowing MCM-41 over HY zeolite particles [MCM-41-HY(C)]. Their HDS activities were tested in a trickle bed reactor at 280–340 °C, total pressure 5.0 MPa, H2/feed ratio 1200 Nm3 m−3 and WHSV 27 h−1, using a solution of 0.8 wt% DBT (dibenzothiophene) in decalin as the feed. A synergetic effect of the components in the mixed supports was observed on the supported Ni-Mo sulfides. NiMo/MCM-41-HY(M) exhibited both high HDS activity and hydrocracking activity, whereas NiMo/MCM-41-HY(C) showed a comparable HDS activity but a much lower hydrocracking activity. Moreover, the increase in HDS activity of either catalyst was accompanied by an enhancement in the hydrogenation pathway. The large difference between NiMo/MCM-41-HY(M) and NiMo/MCM-41-HY(C) in the hydrocracking activity may result from their different pore structures.