NiWO_4/g-C_3N_4的制备及其在离子液体中氧化脱硫性能的研究

采用水热法合成了NiWO_4纳米粒子,然后通过混合煅烧法成功地制备了负载型催化剂NiWO_4/g-C_3N_4。采用XRD、FT-IR、EDS、SEM、BET和XPS表征了NiWO_4/g-C_3N_4的形貌和结构特征。以NiWO_4/g-C_3N_4为催化剂,过氧化氢为氧化剂,1-丁基-3-甲基咪唑四氟硼酸盐离子液体(BMIM]BF4)为萃取剂。考察了催化剂的负载量,过氧化氢、离子液体和催化剂使用量,反应温度,反应时间,不同种类的含硫化合物对脱硫效果的影响。结果表明,在5 m L模拟油,0.2 m L过氧化氢,1.0 m L的BMIM]BF4,0.03 g的NiWO_4/g-C_3N_4,反应温度为80℃,反应时间为140 min的最佳的反应条件下,脱硫率可以达到97.35%。实验表明,NiWO_4/g-C_3N_4具有很好的催化稳定性,催化剂重复使用五次后催化活性并没有明显地降低。

Preparation of NiWO4/g-C3N4 and its ultra-deep desulfurization properties in ionic liquid

The NiWO₄ nanoparticles were synthesized by hydrothermal method. The supported catalysts NiWO₄/g-C₃N₄ were prepared by a simple mixing-calcination method. XRD, FT-IR, EDS, SEM, BET and XPS were used to characterize the morphology and structure of NiWO₄/g-C₃N₄. The prepared NiWO₄/g-C₃N₄ was used as catalyst, hydrogen peroxide as oxidant, 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid (BF₄) as extractant for oxidative desulfurization. The effects of catalyst loading, the amount of hydrogen peroxide, ionic liquid and catalyst, reaction temperature, reaction time, and different sulfur compounds on desulfurization efficiency were studied. The desulfurization rate can reach 97.35% at the optimum reaction conditions:5 mL of model oil, 0.2 mL of hydrogen peroxide, 1.0 mL of BF₄, 0.03 g of NiWO₄/g-C₃N₄, 80 ℃ of reaction temperature and 140 min of reaction time. The results showed that NiWO₄/g-C₃N₄ had good catalytic stability, and the catalytic activity was not significantly reduced after 5 repeated reactions.