Hydrodesulfurization activity of NiMo/TiO2Al2O3 catalysts

Abstract The hydrodesulfurization activities and other physico-chemical properties of NiMo/TiO 2 Al 2 O 3 catalysts were studied and compared with those of a commercial NiMo/Al 2 O 3 catalyst. The TiO 2 Al 2 O 3 mixed oxides carrier was prepared by impregnating Al 2 O 3 with an ethanol solution of TiCl 4 or an isoproponol solution of Ti(C 4 H 9 O) 4 . The active component MoO 3 and the promoter NiO were supported by impregnation of a mixed solution of Ni(NO 3 ) 2 ·6H 2 O and (NH 4 ) 6 Mo 7 O 24 ·4H 2 O. BET measurements showed no large decrease of surface area or pore volume for the carrier and catalyst-containing TiO 2 . LRS data demonstrated that TiO 2 on Al 2 O 3 was present as the anatase phase, and only the vibration band of Mo O at 960 cm −1 appeared over NiMo/TiO 2 Al 2 O 3 when TiO 2 loading was less than 20 wt %. TPS results reveal that the presence of TiO 2 can facilitate sulfidation of Mo O species. Catalytic activity measurements showed that NiMo/TiO 2 Al 2 O 3 catalysts without presulfiding exhibited very high HDS activity for a model reactant containing 100 ppm thiophene or industrial naphtha. The capability of sulphur removal over the non-pretreated NiMo/TiO 2 Al 2 O 3 catalyst is even better than over a sulfided commercial hydrotreating NiMo/Al 2 O 3 catalyst.