Spectroscopic Approach to Electrode Dynamics

电极动力学的光谱方法

• 批准号: 12650803
• 负责人: OSAWA Masatoshi
• 金额: $ 2.11万
• 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: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650803/
• 关键词: Electrochemistry; Surface reaction; Dynamics; Electron transfer; Infrared spectroscopy; Adsorption; Fuel cells; reaction intermediate; 反応速度論; 時間分解赤外分光; 酸化還元反応; 電位振動; 速度論

Although conventional electrochemical methods provide a myriad of kinetics and mechanistic information for heterogeneous redox processes, it is desirable to supplement this with the molecular structural information that can now be provided by in situ surface analytical techniques. Of the techniques available, infrared spectroscopy is well suited for this task since the spectral data can yield valuable information on the identity as well as reactivity of the interfacial species. In this project, surface-enhanced infrared absorption spectroscopy (SEIRAS) was used in the Kretschmann ATR configuration (a prism/thin metal film/solution geometry). The SEIRAS enables us to examine electrochemical reactions with time-resolutions down to microseconds simultaneously with electrochemical measurements. Scanning tunneling microscopy (STM) was also employed for further confirmation of the results obtained by SEIRAS. The main subjects dialed with in this project are as follows:1. Extension of SEIRAS … More to Pt-group metalsThe electrode materials usable for SEIRAS have long been limited only to Au, Ag, and Cu. We succeeded in preparing SEIRA-active electrodes of Pt and other Pt-group metals.2. Electro-oxidation of C1 molecules on Pt catalystsUsing the Pt electrodes mentioned above, catalytic electro-oxidation of small organic molecules was investigated extensively with direct methanol fuel cells in mind. We found for the first time than methanol is oxidized to CO_2 via formate as a reactive intermediate.3. Molecular adsorption at the electrochemical interfaceAdsorption/desorption and reorientation of several molecules on single-crystal electrode surfaces have been investigated as a function of applied potential in conjunction with STM and electrochemical techniques.4. Dynamics of the Dissolution of An Underpotentially Deposited Cu Layer on Au(111)By simultaneous SEIRAS and transient current measurements, two overlapping reaction processes could be separated and analyzed kinetically.5. Electron transfer between electrodes and adsorbed moleculesRedox behaviors of molecules immobilized at electrode surfaces were examined with time-resolved and potential-modulated SEIRAS. Very short-lived intermediates could be detected for some systems. Less

虽然传统的电化学方法提供了大量的动力学和机械信息的非均相氧化还原过程中，它是理想的补充与分子结构的信息，现在可以提供的原位表面分析技术。在现有的技术中，红外光谱非常适合这项任务，因为光谱数据可以产生关于界面物种的身份和反应性的有价值的信息。在这个项目中，表面增强红外吸收光谱（SEIRAS）用于Kretschmann ATR配置（棱镜/薄金属膜/溶液几何结构）。SEIRAS使我们能够在电化学测量的同时以低至微秒的时间分辨率检查电化学反应。扫描隧道显微镜（STM）也被用来进一步确认SEIRAS获得的结果。本课题的主要研究内容如下：1. SEIRAS的扩展 ...更多信息 可用于SEIRAS的电极材料长期以来仅限于Au、Ag和Cu。成功地制备了Pt及其它Pt族金属的SEIRA活性电极. C1分子在Pt催化剂上的电氧化利用上述Pt电极，以直接甲醇燃料电池为对象，对有机小分子的催化电氧化进行了广泛的研究。首次发现甲醇通过甲酸盐作为反应中间体氧化为CO_2.电化学界面上的分子吸附结合扫描隧道显微镜和电化学技术研究了几种分子在单晶电极表面的吸附/脱附和重取向随外加电位的变化. Au（111）表面欠电位沉积Cu层溶解的动力学通过同步SEIRAS和瞬态电流测量，可以分离和动力学分析两个重叠的反应过程.用时间分辨和电位调制的SEIRAS技术研究了固定在电极表面的分子的氧化还原行为。对于某些系统，可以检测到非常短寿命的中间体。少

项目成果

M.Osawa (分担執筆): "Near-Field Optics and Surface Plasmon Polaritons"S.Kawata (編集)Springer (印刷中). (2001)

M.Osawa（撰稿人）：“近场光学和表面等离子激元”S.Kawata（编辑）Springer（印刷中）。

M.Osawa(分担執筆): ""Near-Field Optics and Surface Plasmon Polaritons", (Topics in Applied Physics, Vol.81)(S.Kawata編)"Splinger (Berlin). 25 (2001)

M.Osawa（撰稿人）：“Near-Field Optics and Surface Plasmon Polaritons”，（应用物理主题，第 81 卷）（S.Kawata 编辑）“Splinger（柏林）。25 (2001)

K.Ataka, G.Nishina, W.-B.Cai, S.-G.Sun, and M.Osawa: "Dynamics of the Dissolution of an Underpotentially Deposited Cu Layer on Au (111) : A combined Time-Resolved Surface-Enhanced Infrared and Chronoamperometric Study"Electrochemistry Communications. 2. 4

K.Ataka、G.Nishina、W.-B.Cai、S.-G.Sun 和 M.Osawa：“Au (111) 上欠电位沉积铜层的溶解动力学：组合时间分辨表面

L.-J.Wan, H.Noda, Y.Hara, and M.Osawa: "Effect of Solution pH on the Structure of a 4-Mercaptopyridine Monolayer Self-Assembled onon Au (111)"Journal of Electroanalytical Chemistry. 489. 68-75 (2000)

L.-J.Wan、H.Noda、Y.Hara 和 M.Osawa：“溶液 pH 值对 4-巯基吡啶单层自组装 onon Au (111) 结构的影响”电分析化学杂志。

H.Noda, T.Minoha, L.-J.Wan, M.Osawa: "Adsorption and Ordered Phase Formation of 2,2'-Bypyridine on Au(111) : A Combined Surface-Enhanced Infrared and STM Study"Journal of Electroanalytical Chemistry. 481・1-2. 62-68 (2000)

H.Noda、T.Minoha、L.-J.Wan、M.Osawa：“Au(111) 上 2,2-联吡啶的吸附和有序相形成：表面增强红外和 STM 的组合研究”Journal of电分析化学481・1-2。