Chemical Imaging of Metal Surfaces at the Solid-Liquid Interface: Effects of Grain Structure on Electrocatalytic Reactions

固液界面金属表面的化学成像：晶粒结构对电催化反应的影响

• 批准号: 2246583
• 负责人: Steven Baldelli
• 金额: $ 45.45万
• 依托单位: University of Houston
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2026-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2246583&HistoricalAwards=false
• 关键词: Chemical; Imaging; Metal; Surfaces; Solid

With support from the Chemical Structure, Dynamics, and Mechanisms-A (CSDM-A) and the Chemical Measurement and Imaging (CMI) Programs in the Division of Chemistry, Professor Steven Baldelli from the University of Houston is using highly sensitive surface techniques to understand how molecules react on polycrystalline electrodes. Chemical reactivity of analytes adsorbed to an electrode depends on the underlying crystallinity of a surface as well as its adjacent grains. Studying these effects require the use of methods that reveal surface crystallography, depend on the electrode surface electronic state and symmetry, and impact local vibrational information about the adsorbed molecules. By controlling the system electrochemically, Professor Baldelli and his students will map surface chemistry and link it to underlying crystallography to develop a physical understanding of how crystalline domains influence heterogeneous catalysis. Graduate, undergraduate, and high school students will be mentored and collaborate through this research. Students will develop skills related to instrument building, data analysis, and spectral and microscopy image interpretation.This project uses in situ sum frequency generation vibrational spectroscopy/microscopy (SFG) to probe molecules adsorbed to an electrode while second harmonic generation microscopy (SHG) assists in the determination of the electronic state and symmetry of the electrode. Because SHG anisotropy is related to surface crystallography, the combination of these techniques results in the generation of correlated maps of surface chemistry and underlying crystallography. Surface reactivity is then interrogated using cyclic voltammetry with sub-micron resolution under reaction conditions. In so doing, impacts of adjacent grains in a polycrystalline surface are evaluated. Broader impacts of this work have the potential to advance surface sensitive spectroscopy and microscopy tools that could advance the chemical and physical understanding of how the electrode influences heterogeneous electrocatalysis.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在化学结构，动力学和机制-A（CSDM-A）和化学测量和成像（CMI）计划的支持下，休斯顿大学的Steven Baldelli教授正在使用高度敏感的表面技术来了解分子如何在多晶电极上反应。吸附到电极上的分析物的化学反应性取决于表面及其相邻晶粒的潜在结晶度。研究这些效应需要使用的方法，揭示表面晶体学，依赖于电极表面的电子状态和对称性，并影响局部振动信息的吸附分子。通过电化学控制系统，Baldelli教授和他的学生将绘制表面化学，并将其与基础晶体学联系起来，以发展对结晶域如何影响多相催化的物理理解。研究生，本科生和高中生将通过这项研究指导和合作。学生将培养与仪器制造、数据分析以及光谱和显微图像解释相关的技能。该项目使用原位和频振动光谱/显微镜（SFG）探测吸附在电极上的分子，而二次谐波发生显微镜（SHG）有助于确定电极的电子状态和对称性。由于SHG各向异性与表面晶体学有关，因此这些技术的组合导致产生表面化学和底层晶体学的相关图。然后使用循环伏安法在反应条件下以亚微米分辨率询问表面反应性。在这样做时，评估多晶表面中相邻晶粒的影响。这项工作的更广泛的影响有可能推进表面敏感光谱和显微镜工具，可以推进电极如何影响多相电催化的化学和物理理解。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。