NiWO_4的制备及其在离子液体中深度氧化脱硫的应用

Preparation of NiWO_4 Catalyst and Its Application in the Oxidation Desulfurization of Model Oil

采用水热法合成了不溶于水的NiWO_4纳米粒子。采用XRD、SEM、EDS和BET表征了NiWO_4纳米材料的形貌和结构特征。以NiWO_4作为催化剂,H_2O_2作为氧化剂,1-乙基-3-甲基咪唑硫酸乙酯离子液体([EMIM][EtSO_4])作为萃取剂氧化脱除模拟油中的二苯并噻吩(DBT)。考察了不同氧化脱硫体系,氧化剂、催化剂和离子液体用量,反应温度对脱硫效果的影响,也比较了不同种类含硫化合物的脱除效果。结果表明,在温和的操作条件下NiWO_4就具有很好的脱硫活性。在5.00 mL模拟油,0.20 mL H_2O_2,0.50 mL[EMIM][EtSO4],0.01g NiWO_4,反应温度80℃,反应时间160 min的最佳条件下,模拟油中DBT的脱除率可以达到98.46%。NiWO_4具有很好的催化稳定性,重复使用10次催化活性没有明显降低。此外,讨论了NiWO_4催化氧化脱硫反应机理。

The water-insoluble NiWO_4 nanoparticles were successfully prepared by hydrothermal method.The morphology and structure characteristics of the prepared NiWO_4 were characterized by XRD,SEM,EDS and BET.The oxidative desulfurization of model oil containing DBT was carried out with NiWO_4 as catalyst,H_2O_2 as oxidant agent and 1-ethyl-3-methylimidazolium ethylsulfate（[EMIM][EtSO4]）as extractant.The influences of the different oxidative desulfurization system,the amount of H_2O_2,NiWO_4 and [EMIM][EtSO_4],temperature on the desulfurization rate were investigated.The oxidative desulfurization of different kinds of sulfur-containing compounds in this oxidative desulfurization system was also discussed.The results showed that NiWO_4 possessed excellent desulfurization activity under mild operative conditions.Under the optimal reaction conditions,which were V（Oil）=5.00 mL,V（H_2O_2）=0.20 mL,V（ILs）=0.50 mL,m（NiWO_4）=0.01 g,T=80℃and t=160min,the desulfurization rate for DBT reached 98.46%.NiWO_4 could be recycle used at least ten times without any clearly decrease in catalytic activity.In addition,the reaction mechanism of the oxidative desulfurization was investigated.