EFFECT OF CATALYST PREPARATION CONDITIONS ON THE HYDRODESULFURIZATION OF THIOPHENE OVER Co-Mo/γ-AlO.

The purpose of this research was to study the effects of preparation conditions on the catalytic properties of the Co-Mo/γ-AlO catalyst. The work included catalyst preparations and reactions. In the preparations, cobalt-impregnated Mo/γ-AlO (designated as IcIM) was found to have a promoting effect on the hydrodesulfurization (HDS) of thiophene. Activity and stability of IcIM was higher than that of Mo/γ-AlO. Conversely, when cobalt was added onto Mo/γ-AlO by the mechanical mixing method, no promoting effect was observed. Mo/γ-AlO was also prepared using the two different methods (incipient impregnation or mechanical mixing). The differently prepared Mo/γ-AlO resulted in no obvious difference in activity of IcIM. It was further found that Co-Mo/γ-AlO activity initially increased appreciably with Mo content and leveled off at Mo contents above 9 wt.%. The catalyst exhibited a maximum activity at Co/Mo ratio 0.3. The order in which metal species were added had a great influence on the activity of the Co-Mo/γ-AlO catalyst. Higher activity was obtained when Co was added into Mo/γ-AlO as opposed to Mo added into Co/γ-AlO.