Applicability of reaction rate in gas phase data to supercritical water region

气相数据反应速率对超临界水区域的适用性

• 批准号: 15560660
• 负责人: TAKAHASHI Kenji
• 金额: $ 2.37万
• 依托单位: Kanazawa University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15560660/
• 关键词: hydrated electron; Hydroxyl radical; solvation; dissociative electron attachment; electron affinity; electron transfer; supercritical water; pulse radiolysis

To study reaction rate of OH radical in high temperature water, the most direct method is to observe the transient absorption of OH radical itself. At room temperature there are a several demonstrations for such direct measurements, however, there are few example under high temperature conditions. In the direct UV absorption measurements, the absorption by sapphire windows prevents the measurement of OH signal. The actual absorption intensity due to OH radical was determined by subtraction of the sapphire window signals. The absorption spectra of OH radical in high temperature water shifted to blue. The absorption coefficient of OH radical at 250 nm decreased with increasing the temperature. At room temperature, the absorption coefficient of OH radical is known as to be 500. At 300 C, we found that the absorption coefficients decreased to 200.The temperature dependence of OH radical reaction rate was examined. The rates are followed by the Arrhenius temperature dependence up to 125 C. Above 125 C, however, the reaction rates are independent on the water temperature. The reaction rate at 125 C was 1x10^<10> M^<-1>s^<-1>.

要研究OH自由基在高温水中的反应速率，最直接的方法是观察OH自由基本身的瞬时吸收。在常温下，这种直接测量方法已经有了几个例子，但在高温条件下，这种直接测量的例子很少。在直接紫外吸收测量中，蓝宝石窗口的吸收阻碍了对OH信号的测量。通过减去蓝宝石窗口信号，确定了由于OH自由基引起的实际吸收强度。在高温水中，OH自由基的吸收光谱向蓝移。随着温度的升高，羟基自由基在250 nm处的吸收系数减小。在室温下，OH自由基的吸收系数为500。在300℃时，吸收系数降至200。考察了羟基自由基反应速率与温度的关系。在125℃以下，反应速率与阿累尼乌斯温度有关，但在125℃以上，反应速率与水温无关。在125℃时，反应速率为1×10^~(-1)~(-1)；S~(-1)~(-1)。

项目成果

Reaction rates of the hydrated electron with N2O in high temperature water and potential surface of the N2O- anion

• DOI: 10.1016/j.cplett.2003.11.050
• 发表时间: 2004-01-15
• 期刊: CHEMICAL PHYSICS LETTERS
• 影响因子: 2.8
• 作者: Takahashi, KJ;Ohgami, S;Jonah, CD
• 通讯作者: Jonah, CD

Kenji Takahashi: "Reaction rates of the hydrated electron with N_2O in high temperature water and potential surface of the N_2O anion"Chemical Physics Letters. 383. 445-450 (2004)

Kenji Takahashi：“高温水中水合电子与N_2O的反应速率和N_2O阴离子的电位表面”《化学物理快报》。

Pulse radiolysis of supercritical water. 3. Spectrum and thermodynamics of the hydrated electron

• DOI: 10.1021/jp0457141
• 发表时间: 2005-02-24
• 期刊: JOURNAL OF PHYSICAL CHEMISTRY A
• 影响因子: 2.9
• 作者: Bartels, DM;Takahashi, K;Jonah, CD
• 通讯作者: Jonah, CD

Pulse Radiolysis of Supercritical Water. III. Spectrum and thermodynamics of the hydrated electron

超临界水的脉冲辐射分解。

• 发表时间: 2005
• 期刊: J.Phys.Chem.A 109
• 作者: David M.Bartels