膨润土负载磷钼酸催化碘离子氧化反应的研究

Research on catalytic oxidation reaction of iodine ions by bentonite-phosphomolybdic acid catalysts

采用恒温浸渍蒸发法制备负载型磷钼酸/膨润土(PMo/BEN)催化材料。通过FT-IR、XRD、BET、SEM等对其结构加以表征。以过氧化氢为氧化剂,运用PMo/BEN催化碘离子氧化,同时考察催化剂的负载量、反应温度、溶液pH、过氧化氢用量等因素对反应速率的影响。结果表明:PMo高度分散在BEN表面上,PMo/BEN具有良好的催化活性。在温度为55℃、pH为1.7、过氧化氢浓度为3.6×10-3 mol/L、负载量为8%的条件下,其反应速率达到1.65×10-5mol/(L·s),反应速率提高了12倍。反应前10 min碘离子转化成碘单质的转化率高达99%,连续循环使用8次后,前10 min碘离子的转化率仍为95%。

Bentonite supported phosphomolybdic acid catalyst（PMo/BEN） was prepared by the constant-temperature impregnation evaporation method.It was characterized by FT-IR,XRD,BET,and SEM.The oxidation reaction of iodine ion with hydrogen peroxide（H2O2） as oxidant,and with PMo/BEN as catalyst was studied.The influences of load capacity of catalyst,temperature,pH,and addition of H2O2 on the reaction rate were investigated.Results showed that PMo highly dispersed on the surface of BEN and PMo/BEN had good catalytic activity.The reaction rate reached 1.65×10^-5mol/（L·s） under the best conditions（temperature of 55 ℃,pH=1.7,H2O2 concentration of 3.6×10^-3mol/L,and load capacity of 8%）,which 12 times more than the reaction without catalyst.In the catalytic oxidation reaction,the conversion rate of iodine ions converting into iodine was as high as 99% in the first 10 min.The PMo/BEN after cycling 8 times still showed superior activity,which maintained a conversion rate of 95%.