对"过氧化氢碘化钾催化分解"催化概念的质疑

在过氧化氢中加入碘化钾溶液，过氧化氢的分解速率显著加快．国内外文献普遍认为这是碘化钾在起催化剂作用．我们发现反应过程中溶液颜色变黄．进一步的实验表明，溶液中碘离子浓度降低、溶液的电导率增大、pH值升高，而且溶液中生成了单质碘．根据对上述实验研究结果，我们对碘化钾作为过氧化氢分解反应的催化剂的概念提出了质疑。并证实发生了过氧化氢氧化碘化钾的化学反应．

Challenge the opinion that potassium iodide acts as a catalyst in the reaction of hydrogen peroxide decomposition

We have been taught by domestic and overseas physicochemistry experiment textbooks that potassium iodide acts as a catalyst in the reaction of hydrogen peroxide decomposition, but we found recently that the color of the solution changed to yellow and confirmed the existence of iodine in the solution after the two reactants were mixed. Instruments such as pH meter, conductometer and iodic ionselectiveelectrode were employed to detect the change of pH, conductivity and concentration of iodic ion during the reaction so as to explain the phenomena. The results of experiments show that the conductivity and pH of the solution increased and the concentration of iodic ion decreased. Conclusions could be obtained from the results that the opinion taking potassium iodide for catalyst of hydrogen peroxide decomposition is wrong and that some potassium iodide is oxidized into iodine and potassium oxide by hydrogen peroxide causing the color change, the conductivity and pH increase, and the concentration of iodic ion decrease.