CAS: Single-Molecule Specific Voltammetry: Quantifying Reaction Products of Electrocatalysis at Single Particle Level

在化学测量与成像项目的支持下，以及大分子、超分子和纳米化学项目的部分共同资助；化学催化;化学结构、动力学和机制——A，张教授和他在马萨诸塞大学达特茅斯分校的研究小组正在开发一种新的化学分析工具，以详细研究与二氧化碳（CO2）转化为更少有害物质相关的电化学反应机制，这是缓解气候变化的一条有希望的途径。具体来说，该团队正在开发一种名为单分子特异性（SMS）伏安法的新技术，以探测单个纳米颗粒作为二氧化碳还原反应催化剂的性能。这项研究可能会提高我们设计电催化剂的能力，有效地将二氧化碳转化为燃料。一个广泛的教育计划将这项研究介绍给本科生和研究生，并包括外展活动，以激励南马萨诸塞州代表性不足的K-12学生在STEM领域从事职业。本项目旨在建立一个平台来量化单个纳米粒子上电化学还原CO2的产物，并揭示纳米电催化剂的性能和稳定性依赖于形貌。在金纳米颗粒上形成一氧化碳（CO）被用作模型反应。具体而言，该研究旨在实现以下目标：(1)证明单分子特异性（SMS）伏安法量化单个纳米颗粒上CO形成的能力。(2)评价颗粒间和颗粒内非均质性对单一电催化剂CO生成的影响。(3)确定CO2还原反应中纳米颗粒不稳定性的机理。通过结合SMS伏安法、超分辨荧光和电子显微镜，研究小组正在努力阐明CO形成的形态依赖活性，并超分辨单个纳米电催化剂上的面依赖活性位点。提高对电催化剂的活性和稳定性之间的关系的理解以及二氧化碳还原中纳米颗粒不稳定性的来源是平行的目标。这些研究工作旨在为合理设计用于二氧化碳还原反应的纳米电催化剂提供所需的知识。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the Chemical Measurement & Imaging program, and partial co-funding from programs in Macromolecular, Supramolecular, and Nanochemistry; Chemical Catalysis; and Chemical Structure, Dynamics, and Mechanisms – A, Professor Chang and his research team at the University of Massachusetts - Dartmouth are developing a new chemical analysis tool to enable detailed studies of electrochemical reaction mechanisms associated with conversion of carbon dioxide (CO2) to less harmful materials, a promising route to mitigating climate change. Specifically, the team is developing a novel technique, named single-molecule specific (SMS) voltammetry, to probe the performance of single nanoparticles as catalysts for CO2 reduction reactions. The research may advance our ability to design electrocatalysts that efficiently convert CO2 into fuels. A broad educational program introduces this research to undergraduate and graduate students, and includes outreach activities to inspire underrepresented K-12 students in South Massachusetts to pursue careers in STEM fields.This project aims to develop a platform to quantify the products of electrochemical CO2 reduction on single nanoparticles, and to reveal the morphology-dependent performance and stability of nanoelectrocatalysts. Carbon monoxide (CO) formation on Au nanoparticles is used as a model reaction. Specifically, the research is addressing the following objectives: (1) Demonstration of the ability of single-molecule specific (SMS) voltammetry to quantify CO formation on single nanoparticles. (2) Assessment of the effects of interparticle and intraparticle heterogeneity on CO formation on single electrocatalysts. (3) Identification of the mechanism(s) of nanoparticle instability during CO2 reduction reactions. By combining SMS voltammetry, super-resolution fluorescence, and electron microscopies, the research team is striving to elucidate the morphology-dependent activity for CO formation and super-resolve the facet-dependent active sites on single nanoelectrocatalysts. Improved understanding of the correlation between the activity and stability of electrocatalysts and the origin of nanoparticle instability in CO2 reduction are parallel aims. These research efforts are envisioned to provide the knowledge needed for rational design of nanoelectrocatalysts for CO2 reduction reactions.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.