硫代硫酸根插层水滑石的层间限域反应

Interlayer Reaction of Thiosulfate in a Confined Region of Layered Double Hydroxides

将无机阴离子硫代硫酸根(S2O23-)限域在锌铝水滑石(LDH)层间,并研究了其在水滑石层板限域空间内被铁氰根(Fe(CN)63-)氧化的反应过程.通过X射线衍射(XRD)和傅里叶变换红外(FTIR)光谱仪对反应的中间产物和最终产物进行的表征发现,氧化产物连四硫酸根(S4O62-)进入到溶液中,还原产物亚铁氰根(Fe(CN)64-)则保留在水滑石层间.进一步系统研究了该反应的动力学过程,考察了硫代硫酸根插层水滑石用量、铁氰化钾浓度和温度对反应的影响.结果表明该氧化还原反应符合球体内扩散模型.根据温度对反应速率影响,得出了该反应的表观活化能为24.6kJ.mol-1,比相同条件下溶液中反应活化能降低了约13.7kJ.mol-1.采用分子动力学(MD)模拟计算了水分子含量对硫代硫酸根插层水滑石层间距大小的影响.计算表明:在水溶液环境中,水滑石微反应器的尺寸在特定方向具有可调控性.根据实验表征和理论计算对该层间反应的机理进行了探讨.因此,该类层状材料可以作为一种新型纳米级微反应器应用于调控化学反应.

The thiosulfate anion （S2O32-） was intercalated into a ZnAI layered double hydroxide （LDH）, and its oxidation reaction with hexacyanoferrate（lll） （Fe（CN）63-） in the confined region between the layers of LDH has been discussed. Based measurements of the intermediate state and final product using X-ray diffraction （XRD） and Fourier transform infrared （FTIR） spectroscopy, the oxidation product tetrathionate （S4O62-） dissolved in solution, while the reduction product hexacyanoferrate （11） existed in the interlayer of the LDH. Furthermore, the kinetics of this reaction were investigated in batch mode. The influences of the initial Fe（CN）63- concentration, ZnAI-S203 LDH quantity, and reaction temperature on the oxidation reaction were studied. The reaction follows a diffusion-controlled process represented by Crank-Ginstling and Brounstein model with the apparent activation energy of 24.6 kJo moL-1, which was about 13.7 kJ. mo1-1 less than that of the solution reaction under the same conditions. The influence of water content on interlayer spacing was simulated by molecular dynamics. The simulation result shows that the size of this microreactor can be regulated in a certain orientation in the solution environment. From the experimental results and theoretical calculation, we propose a mechanism for the interlayer reaction. This layered material can be used as a novel nano-reactor to regulate the rate of chemical reactions.