Effect of impregnation sequence of Mo and Ni on the performance of Mo-Ni/Al₂O₃ catalyst in thioetherification

Mo-Ni/Al₂O₃ catalysts were prepared by different impregnation sequences of Mo and Ni; the effect of impregnation sequence on the performance of Mo-Ni/Al₂O₃ catalysts in thioetherification was investigated. The results showed that the activity of the catalyst obtained by first impregnating Mo and then Ni (SI-mn) is close to that prepared by co-impregnation of Mo and Ni (MN); both are much more active than the catalyst obtained by first impregnating Ni and then Mo (SI-nm). For the SI-mn catalyst, Mo loaded on Al₂O₃ at the first stage can weaken the interaction between Ni and supporter, leading to a strong electronic effect between Ni and Mo, which can promote the formation of active phase in the presulfidation process and then enhance the catalytic performance of Mo-Ni/Al₂O₃ in thioetherification and selective hydrogenation of diene. Similar phenomena are observed for the MN catalyst obtained by co-impregnation, which also exhibits high activity in thioetherification.