In situ Time-Resolved Spectroscopic Studies of Redox Reactions Involving Adsorbed Species

凯斯西储大学的Daniel A.Scherson教授由化学系化学测量和成像计划支持，研究水溶液中分子和离子形式的氮和硫氧化物以及与能量转换和电合成相关的其他物种的反应机理。重点是开发和实施光谱技术，以便在纳秒范围内原位监测这类物种的时间演化和控制反应路径的因素。这些研究的结果将为解决与环境控制和补救有关的社会问题开辟新的前景，例如过度使用化肥以及能源储存和转换所产生的问题。本项目的重点是这些反应中不可逆吸附的电催化剂的原位静态和动态表征，以及选定的裸露和原子修饰的单晶金属表面的微地形对吸附中间体性质和其他界面性质的影响。通过耦合微电极、电荷注入和一系列基于显微镜的互补光谱技术，包括紫外可见反射光谱、共振和表面增强拉曼光谱以及和频和二次谐波产生，可以深入了解这些问题。这项工作的成功将为将原位光谱电化学技术扩展到纳秒范围提供一种手段，使人们能够研究与各种其他领域相关的电子转移事件的动态方面，包括电催化、多相催化、腐蚀、传感器和环境科学。参与这项研究的学生将接受广泛的基础学科和应用学科的培训。

Professor Daniel A. Scherson of Case Western Reserve University is supported by the Chemical Measurement and Imaging program of the Division of Chemistry to investigate the mechanism of reactions involving nitrogen and sulfur oxides both in molecular and ionic forms in aqueous solutions, as well as other species of relevance to energy conversion and electrosynthesis. Emphasis is centered on the development and implementation of spectroscopic techniques for monitoring in situ the time evolution of such species in the nanosecond domain and the factors that control the reaction pathways. The results emerging from these studies will open new prospects for addressing societal problems associated with environmental control and remediation, such as those derived from the overuse of fertilizers, and energy storage and conversion. This project focuses on the in situ static and dynamic characterization of irreversibly adsorbed electrocatalysts for these reactions, as well as the effect of the microtopography of selected bare and atom-modified single crystal metal surfaces on the nature of adsorbed intermediates and other interfacial properties. Insight into these issues will be gained from the coupling of microelectrodes, charge injection, and an array of complementary microscope-based spectroscopic techniques, including UV visible reflection spectroscopy, resonance and surface enhanced Raman spectroscopies, and sum frequency and second harmonic generation. The success of this work would provide a means for extending in situ spectroelectrochemical techniques into the nanosecond range, allowing the study of the dynamic aspects of electron transfer events of relevance to a variety of other fields, including electrocatalysis, heterogeneous catalysis, corrosion, sensors, and environmental science. Students involved in this research will be trained in a broad range of fundamental and applied disciplines.