Selectivity enhancement of CoMoS catalysts supported on tri-modal porous Al 2 O 3 for the hydrodesulfurization of fluid catalytic cracking gasoline

Abstract

Abstract To improve the selectivity performance of CoMoS catalysts applied to the hydrodesulfurization (HDS) of fluid catalytic cracking (FCC) gasoline, a series of CoMoS/Al 2 O 3 catalysts was prepared with alumina of different pore structures, and their HDS performance was evaluated with a real FCC gasoline. This study indicated that CoMoS/Al 2 O 3 catalysts prepared with micro- or meso-porous alumina possessed high HDS activity but low selectivity, whereas macro-porous alumina enhanced the selectivity of CoMoS catalysts. The enhanced HDS selectivity was due to the tuning of the MoS 2 slabs and the weakening of the internal diffusion resistance. Based on the above results, the optimal CoMoS/Al 2 O 3 catalyst was prepared with the alumina of the tri-modal pore distribution at approximately 5–8 nm, 15–20 nm, and 90–100 nm. The optimal catalyst displayed a balanced HDS activity and selectivity in contrast to the reference catalyst prepared with K- and P-modified Al 2 O 3 .