Salt effect on ionic reactions in supercritical water

盐对超临界水中离子反应的影响

• 批准号: 13650823
• 负责人: TAKAHASHI Kenji
• 金额: $ 2.3万
• 依托单位: Hokkaido University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650823/
• 关键词: Reaction rate; Hydrated electron; Hydroxyl radical; Solvation; Electron transfer; ヒドロキシルラジカル; イオン対; 誘電率; クーロンポテンシャル; 放射線分解; 水和; アレニウス; 水素イオン

Temperature ahd pressure effects on reactions of hydrated elelctrons and OH radical have been studied near the critical temperature of water. The reaction rates were measured using pulse radiolysis technique. The time resolution is about 5 nano-seconds. Reaction between hydrated electron and nitrobenzene is close to a diffusion limit. The reaction rate, however, sharply slow down near the critical temperature. Reaction rates between hydrated electron and N_2O can be explained by the Marcus electron transfer model.Reaction rates of OH radical with H_2 in high temperature water are 10 times faster than those in gas phase. Near 350 C, however, the reaction rates in water slow down and approach to the reaction rate in gas phase. These differences in the reaction rates can be explained by considering hydration of reactants including transition state. A similar reaction model predicts that reaction of OH with benzene in water could be faster than that in gas phase even near 350 C. Therefore the reaction rates of OH with benzene in gas phase cannnot be applicable in high temperature water.

在水的临界温度附近，研究了温度和压力对水合电子与羟基自由基反应的影响。用脉冲辐解技术测量了反应速率。时间分辨率约为5纳秒。水合电子与硝基苯的反应接近扩散极限。然而，在临界温度附近，反应速度急剧减慢。水合电子与N_2O的反应速率可用Marcus电子转移模型来解释，在高温水中，OH自由基与H_2的反应速率比在气相中快10倍。在350℃附近，水中的反应速度变慢，接近气相中的反应速度。这些反应速率的差异可以通过考虑包括过渡态在内的反应物的水合作用来解释。一个相似的反应模型预测，在350℃附近，OH与苯在水中的反应速度可能比在气相中的反应速度快，因此，在高温水中，OH与苯在气相中的反应速率不适用。

项目成果

Timothy W.Marin: "Pulse radiolysis of supercritical water II. Reaction of nitrobenzene with hydrated electrons and hydroxyl radicals"J. Phys. Chem. A.. 106. 12270-12279 (2002)

Timothy W.Marin：“超临界水的脉冲辐射分解 II。硝基苯与水合电子和羟基自由基的反应”J。

荒井康彦: "超臨界流体のすべて"テクノシステム. 800 (2002)

Yasuhiko Arai：“关于超临界流体”Techno System 800 (2002)。

Jason A.Cline: "Pulse radiolysis of supercritical water I. Reactions between hydrophobic and anionic species."J. Phys. Chem. A.. 106. 12260-12269 (2002)

Jason A.Cline：“超临界水的脉冲辐射分解 I。疏水性物质和阴离子物质之间的反应。”J。

Kenji Takahashi: "Reaction rates of the hydrated electron with NO2-, NO3-, and hydronium ions as a function of temperature from 125 to 380℃"Chem. Phys. Lett.. 357. 358-364 (2002)

Kenji Takahashi：“水合电子与 NO2-、NO3- 和水合氢离子的反应速率随温度变化（从 125 到 380℃）”Chem. Phys. 357. 358-364 (2002)

Jason A. Cline: "Pulse radiolysis of supercritical water I. Reactions between hydrophobic and anionic species"J. Phys. Chem. A. 106. 12260-12269 (2002)

Jason A. Cline：“超临界水的脉冲辐射分解 I. 疏水性物质和阴离子物质之间的反应”J。