活性金属不同浸渍顺序对Mo-Ni/Al2O3催化剂硫醚化反应性能的影响

针对硫醚化反应过程使用的Mo-Ni/Al₂O₃催化剂，考察了不同浸渍方法对其催化性能和表面结构性质的影响。结果表明，通过同步浸渍和分步浸渍方法制得Mo-Ni/Al₂O₃催化剂的活性顺序为：先浸渍Mo后浸渍Ni的催化剂（SI-mn）≈Ni和Mo共同浸渍的催化剂（MN）>先浸渍Ni后浸渍Mo的催化剂（SI-nm）。对于SI-mn催化剂，先负载Mo后减弱了二次浸渍的Ni金属与载体间的相互作用，有利于负载金属的活化，并在二次浸渍后焙烧过程显现出显著的电子效应，形成新的Mo-Ni前体物种，有利于在预硫化过程形成适宜硫醚化和二烯烃选择性加氢的活性中心相，促进硫醚化反应和二烯烃选择性加氢。对于共同浸渍的MN催化剂也有类似的性质，因而也具有较好的催化性能。

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.