SiO2负载 Keggin 型磷钨钒杂多酸的催化剂的制备及其降解罗丹明 B 的研究

摘要

The Keggin-type phosphotungstovanadic heteropolyacid catalyst was synthesis by Na2 HPO 4 ,NaVO 3 and Na2 WO 4 ·2 H 2 O.Then,[Bmim]4 PW1 1 VO 40 heteropolyacid hybrid materials was prepared by reacting H3PMo12O40 with 1-butyl-3-methylimidazolium bromide ionic liquid.The prepared catalyst was characterized by XRD and IR,and the results showed a characteristic Keggin-type structure of [Bmim]4 PW1 1 VO 40 .[Bmim]4 PW1 1 VO 40/SiO 2 catalyst was prepared using SiO 2 as the support.The suppoted catalyst was then applied as catalyst for the degradation of Rhodamine B using the H 2 O 2 as the oxidant. The obtained optimal reaction conditions was 3 mL of H 2 O 2 ,the weight of [Bmim]4 PW1 1 VO 40 20% loading,0.35 g of catalyst at 40 ℃ for 1.5 h.Under the optimal condition,the degradation rate of Rhodamine B was up to 98.4%.The catalyst shoed good reusability and can be reused for many times without the decrease of degradation activity of Rhodamine B .%利用 Na2 HPO 4、NaVO 3和 Na2 WO 4·2 H 2 O 合成了 Keggin 型 H 4 PW11 VO 40杂多酸,并将其与1-丁基-3-甲基咪唑溴离子液体反应,生成[Bmim]4 PW11 VO 40杂多化材料。利用 XRD 和 IR 对催化剂进行表征,结果表明,所合成的催化剂具有 Keggin 型结构。以 SiO 2为载体制备了负载型的杂多酸催化剂[Bmim]4 PW11 VO 40/SiO 2,以 H 2 O 2为氧化剂,考察了 H 2 O 2体积、催化剂质量、反应温度、反应时间等因素对罗丹明 B 降解率的影响。实验结果表明,最优的反应条件为：H 2 O 2体积为3 mL、催化剂质量为0.35 g、反应温度为40℃、反应时间为1.5 h。在此条件下,罗丹明 B 的降解率达98.4%。催化剂具有良好的重复使用性能,多次重复使用后,罗丹明 B 的降解率没有明显的降低。