Scanning Electrochemical Microscopy and Ultramicroelectrode Studies of Electrocatalysis at Nanoparticle Ensembles of Microdimensions and at Single Nanoparticles

微米尺寸纳米颗粒集合体和单个纳米颗粒电催化的扫描电化学显微镜和超微电极研究

• 批准号: 1757127
• 负责人: Cynthia Zoski
• 金额: $ 27.29万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2020-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1757127&HistoricalAwards=false
• 关键词: Scanning; Electrochemical; Microscopy; Ultramicroelectrode; Studies

In this project funded by the Chemical Measurement and Imaging Program of the Division of Chemistry, Professor Cynthia Zoski of New Mexico State University is studying electrocatalysis at finite nanoparticle ensembles and single nanoparticles on conducting surfaces of ultramicrodimensions where kinetic investigations are carried out under high mass transport conditions. Nanoparticles are an important part of the overall catalyst design in energy devices such as fuel and solar cells. These studies provide wide-ranging knowledge on the relationship between nanoparticle size, distribution, and catalytic activity. These studies also address a key issue in electrocatalysis regarding the nature of intermediates and adsorbed species on a catalyst surface while the electrode reaction occurs, which aid in diagnosis of reaction mechanisms, with relevance to molecular recognition, sensing, and to infectious diseases where biofilm integrity and the relationship to quorum sensing and bacteria micro-colonies are of interest. Broader impacts also include training of post-doctoral fellows and graduate students in multi-disciplinary scientific research in areas of national importance, and developing a new course in advanced electrochemical techniques which targets post-doctoral fellows, graduate and senior undergraduate students from chemistry, chemical engineering, physics, and biology.This project focuses on electrocatalysis at nanoparticle ensembles and single nanoparticles, development of simulations to describe their behavior, fabrication and analysis of ensemble and single nanoparticle electrodes through single nanoparticle collisions at ultramicroelectrodes, and the use of scanning electrochemical microscopy to study the kinetics and nature of the reactivity of electrogenerated oxide films and those adsorbed as a result of an electrocatalytic reaction. The collision approach to nanoparticle electrodes allows control over the number of nanoparticles on a surface, flexibility in selection of the electrode material and nanoparticle type (e.g. metallic, core shell, alloy) and size, and a direct comparison between finite ensemble and single nanoparticle kinetics at the same electrode. The shape of collision transients provides insight into the microscopic details of the nature of nanoparticle interaction with an electrode and the kinetics of electrocatalytic reactions such as oxygen reduction at single nanoparticles. Using transient surface interrogation scanning electrochemical microscopy to study the nature and reactivity of oxide films overcomes the difficulties in traditional electrochemical experiments where the working electrode itself is used to find intermediates and the response is convoluted with the current from the electrolysis and capacitive charge.

在化学划分的化学测量和成像计划资助的项目中，新墨西哥州立大学的Cynthia Zoski教授正在研究有限的纳米颗粒结合体和单纳米颗粒的电催化，并在高质量运输条件下进行动力学调查的超核测试表面。纳米颗粒是燃料和太阳能电池等能源设备总体催化剂设计的重要组成部分。这些研究提供了有关纳米颗粒大小，分布和催化活性之间关系的广泛知识。这些研究还解决了电催化性质的一个关键问题，这些问题在发生电极反应的同时，在催化剂表面上的性质和吸附物种，这有助于诊断反应机制，与分子识别，感应和感染性疾病有关，以及与生物食物完整性以及与Quorum Sensing and Quorum Sensing and Cacteria microy-Colonies相关的感染性疾病。 Broader impacts also include training of post-doctoral fellows and graduate students in multi-disciplinary scientific research in areas of national importance, and developing a new course in advanced electrochemical techniques which targets post-doctoral fellows, graduate and senior undergraduate students from chemistry, chemical engineering, physics, and biology.This project focuses on electrocatalysis at nanoparticle ensembles and single nanoparticles, development of通过单纳米粒子碰撞来描述其行为，制造和分析在超核电极上的碰撞，以及使用扫描电化学显微镜来研究电源膜和那些吸附的电气反应的吸附性氧化物的反应性的动力学和性质。 纳米颗粒电极的碰撞方法可以控制表面上纳米颗粒的数量，选择电极材料和纳米颗粒类型的灵活性（例如金属，核心壳，合金）和大小之间的直接比较以及有限的集合和同一电子电极上的单纳米颗粒动力学。碰撞瞬变的形状可洞悉纳米颗粒相互作用与电极相互作用的性质的微观细节以及电催化反应的动力学，例如单纳米颗粒上的氧气还原。 使用瞬态表面询问扫描电化学显微镜研究氧化物膜的性质和反应性克服了传统的电化学实验中的困难，在这些实验中，使用工作电极本身来查找中间体，并且反应与电解和电容电荷的电流相处。