Preparation of MoO3/Al2O3 Catalysts with Sharp Eggshell Mo Distribution by Slurry Impregnation

MoO₃/Al₂O₃ catalysts with eggshell Mo concentration profiles were prepared by reaction of Al₂O₃ extrudates or balls with slurry of MoO₃ in water. The Mo concentration wave penetrating Al₂O₃ particles during this slurry impregnation was almost rectangular. Its height was close to the filled monolayer loading. The thickness of the shell was regulated either by impregnation time or by the MoO₃ amount in the slurry. The hydrodesulfurization activity of Mo species deposited by slurry impregnation was about the same or better (depending on the Al₂O₃ used) as in industrial MoO₃/Al₂O₃ catalyst.