Ni掺杂量对高活性NiMoS2/TiO2催化剂加氢脱硫性能的影响

Effects of Ni doping amount on hydrodesulfurization of high activity NiMoS2/TiO2 catalyst

以气相二氧化钛为载体,硫代乙酰胺为硫源,钼酸铵为钼源制备了高活性负载型二硫化钼催化剂。采用浸渍法引入助剂镍,对不同镍掺杂量的催化剂进行了研究。在固定床高压微反应装置上,以有机含硫化合物二苯并噻吩(DBT)为模型化合物,研究了镍的掺杂量对催化剂加氢脱硫性能的影响,并采用X射线光电子能谱(XPS)技术、X射线衍射(XRD)、氮气吸附比表面积(BET)测定对催化剂进行了表征。结果表明:镍的掺杂,使催化剂活性明显提高,当镍钼物质的量比为0.5时,二苯并噻吩的转化率达到97%。Ni在催化剂中的化学状态与其掺杂量有关,掺杂量过高时有NiSx相生成,不利于加氢脱硫反应的进行,同时Ni的掺杂也使其选择性更倾向于直接加氢脱硫方向。

High activity supported MoS2 catalyst is prepared with TiO2(P25)as carrier,CH3CSNH2 as sulfur source and(NH4)6Mo7O24·4H2O as molybdenum source.The catalysts prepared by impregnation method with different doping amount of nickel are studied.The effects of the doping amount of nickel on the hydrodesulfurization(HDS)performance of catalyst are studied in a highpressure fixed-bed micro-reactor with the organic sulfur-containing compound dibenzothiophene(DBT)as the model compound.The catalysts are characterized by X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD)and nitrogen adsorption specific surface area(BET).The results show that the nickel doping significantly increases the activity and the conversion of DBT can reach 97%when the Ni-Mo molar ratio is 0.5.The chemical state of Ni in the catalyst is related to its doping amount.If the doping amount is too high,NiSx phase will be formed,which is not conducive to the HDS reaction.At the same time,Ni doping also makes its selectivity more inclined to direct hydrodesulfurization(DDS)direction.