Time-resolved vibrational spectroscopic study of electrode dynamics

本计画旨在利用快速时间分辨红外光谱技术研究电极反应动力学。表面增强红外吸收光谱（SEIRAS）的使用使皮秒范围内的超快时间分辨研究成为可能。主要研究成果如下：1.超快时间分辨红外光谱研究时间常数为0.1-1 ms的双层充电阻碍了超快电极动力学的研究。通过将所谓的温度跳跃方法与皮秒时间分辨的SEIRAS相结合，第一次规避了这个问题。通过激光脉冲对界面的快速加热，通过水的重新取向导致电势的突然变化。2. SEIRA的技术发展已经开发了在Si和Ge棱镜上制备非常稳定的SEIRA活性金属薄膜电极的简单且成本有效的技术。这些技术为上述皮秒时间分辨红外光谱研究的成功做出了重要贡献。 关于我们 电化学振荡的分析在电化学界面上会发生各种各样的振荡。我们用时间分辨SEIRAS研究了甲酸在Pt电极上氧化过程中的电位和电流振荡，并提出了一个新的概念来解释这种振荡。4.电催化在分子尺度上详细研究了低温燃料电池的基础--Pt电极上C_1分子的析氢、氧还原和阳极氧化。我们首次明确地证明了所有C_1分子都是通过甲酸盐氧化为CO_2的，这完全修正了一般的共识。5.自组装单分子膜的结构与功能作为分子识别系统的模型体系，我们用SEIRAS研究了腺嘌呤衍生物在Au电极上的自组装与缩硫氨酸衍生物之间的氢键配对。我们还成功地利用三钌配合物制备了新型的自组装膜。它们的结构和功能由SEIRAS检查。少

This project aimed at to study electrode kinetics and dynamics by using fast time-resolved infrared spectroscopy. The use of surface-enhanced infrared absorption spectroscopy (SEIRAS) enabled ultrafast time-resolved study in the picosecond range. The main achievements are as follows.1.Ultrafast time-resolved IR spectrscopyDouble-layer charging with a 0.1-1 ms time constant has hampered the study of ultrafast electrode dynamics. This problem was circumvented for the first time by coupling the so-called temperature jump method with picosecond time-resolved SEIRAS. The rapid heating of the interface by a laser pulse results in the sudden change in potential through reorientaion of water.2.Technical developments in SEIRASSimple and cost-effective techniques to prepare very stable SEIRA-active thin metal film electrodes on Si and Ge prisms have been developed. These techniques significantly contributed to the success of the picosecond time-resolved IR studies mentioned above.3.Molecular sca … More le analysis of electrochemical oscillationsA variety of oscillations occur at the electrochemical interface. We investigated potential and current oscillations during formic acid oxidation on Pt by time-resolved SEIRAS and proposed a new concept that explains the oscillations without any assumptions.4.ElectrocatalysisHydrogen evolution, oxygen reduction, and anodic oxidation of C_1 molecules on Pt electrodes that constitute the basis of low temperature fuel cells were examined in detail at the molecular scale. We clearly showed for the first time that all C_1 molecules are oxidized CO_2 via formate, which totally revised the general consensus.5.Structures and functions of self-assembled monolayers (SAMs)Hydrogen bond pairing between an adenine derivative self-assembled on an Au electrode and a thimidine derivative were examined by SEIRAS as a model system of molecular recognition system. We also succeeded in fabricating new types of SAMs using triruthenium complexes. Their structures and functions were examined by SEIRAS. Less