铋/四氧化三铁-壳聚糖催化还原水中对硝基苯酚研究

Study on the reduction of 4-nitrophenol in water catalyzed by Bi/Fe_3O_4-chitosan

将壳聚糖(CS)负载到磁性四氧化三铁(Fe_3O_4)上制得Fe_3O_4-CS,以Fe_3O_4-CS负载铋制得Bi/Fe_3O_4-CS催化剂。考察了此催化剂催化过量的硼氢化钠(NaBH_4)还原对硝基苯酚(4-NP)的效果。实验结果表明反应为准一级反应。在反应温度为25℃、4-NP的浓度为4.0mmol/L、NaBH_4的浓度为160mmol/L、催化剂用量为0.05g时,测得反应速率常数为0.623/min。催化剂重复使用20次活性基本不变。

Bi/Fe_3O_4-chitosan（Bi/Fe_3O_4-CS）catalyst was prepared by reduction of Bi 3＋absorbed in magnetic Fe_3O_4-CS,which was prepared by loading CS on Fe_3O_4.In water the properties of catalyst in the reduction of 4-nitrophenol（4-NP）with excess sodium borohydride were investigated.The results showed that the reaction was in accordance with the pseudo-first-order kinetics.Under the conditions of reaction temperature 25℃,the concentration of 4-NP 4.0mmol/L,the concentration of NaBH_4 160mmol/L and the amount of Bi/Fe_3O_4-CS 0.05 g,the rate constant can reach 0.623/min.The activity of catalyst can maintained after 20 cycles.