ATR-FTIR Spectroscopy of Electrochemical Catalytic Reactions in Aqueous Systems at Doped Diamond Film Electrodes

掺杂金刚石膜电极水体系中电化学催化反应的 ATR-FTIR 光谱

• 批准号: 0931749
• 负责人: Glenn Schrader
• 金额: $ 34.33万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-15 至 2014-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0931749&HistoricalAwards=false
• 关键词: ATR; FTIR; Spectroscopy; Electrochemical; Catalytic

0931749 Schrader Intellectual Merit: The objective of this research is to develop a new methodology for understanding the mechanisms of electro-catalytic conversions of highly functionalized organic compounds in aqueous phase systems. To that end, a powerful in situ technique, attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, will be integrated into the design of an innovative "spectro-electrochemical cell". This device will be used to study solution/electrode interfaces systematically (e.g., as a function of electrode potential, solution pH, and surface functionality). Model organic compounds with key chemical functional groups will be used as probes for elucidating catalytic charge transfer mechanisms, primarily under reductive (cathodic) conditions. Additionally, a series of batch-reaction experiments will be performed in parallel to determine the kinetics of these reductive conversions, including measurements as a function of temperature for determination of activation energies. The experimental data will be complemented with density functional theory (DFT) calculations to augment and validate the mechanistic insights. The combination of in situ ATR-FTIR spectroscopy, kinetic measurements, and DFT calculations will constitute a new methodology for developing a deeper understanding of the mechanisms of electrochemical reactions in aqueous solutions. This new methodology will be demonstrated using conductive boron-doped diamond (BDD) film electrodes. The main advantages of BDD electrodes over traditional glassy carbon, noble metal, and metal oxide electrodes are: 1) high stability under anodic polarization, 2) suppression of water electrolysis reactions, 3) chemical inertness, and 4) low background current and double layer charging. These properties also make BDD films an ideal support for studying the catalytic and electrochemical properties of metal nanoparticles. Although research on BDD electrodes has increased in recent years, a mechanistic understanding of the surface chemistry of the BDD surface and supported metal nanoparticles under in situ conditions has not been developed. The surface chemistry of the BDD surface can change depending on the applied electrode potential and solution conditions and is the governing factor for charge transfer at the solution/electrode interface. These factors dictate the utility of BDD electrodes for a vast number of applications. Broader Impact: BDD electrodes have been successfully shown to have a variety of technological applications: 1) water disinfection and treatment; 2) electrochemical sensing; and 3) electro-synthesis of organic compounds. Their potential use as catalyst supports remains largely untapped, although their application is highly attractive for systems that may involve aqueous environments such as bio-feedstock processing for fuels or "green chemistry" for specialty chemicals production. This project will also increase participation of graduate and undergraduate students from underrepresented groups in engineering research. The graduate students will participate in the Alfred P. Sloan Foundation: American Indian Graduate Partnership Fellowships and Arizona Scholars Program. This program is designed to address the national need for academically - prepared Native Americans who can help spur economic development in their communities and reservations and occupy leadership positions in colleges and universities, government and the corporate world. The project will also provide new expanded opportunities to involve high school and undergraduates in research through the UA Professional Internship Program for High School Seniors, the NASA Space Grant Undergraduate Internship Program, the UA Water Sustainability Undergraduate Fellowship Program, and the UA Summer Research Institute (SRI). The Chemical and Environmental Engineering Department is currently the host for an NSF REU and RET site on "Systems Approach to Sustainability: Manufacturing, Water and Energy" (NSF# 0649202). The proposed research will involve several undergraduates and high school teachers from these programs during each year of the grant.

小行星0931749 智力优势：本研究的目的是开发一种新的方法来理解电催化转化的机制，高度官能化的有机化合物在水相系统。为此，一个强大的原位技术，衰减全反射傅里叶变换红外光谱（ATR-FTIR），将被集成到一个创新的“光谱电化学池”的设计。该装置将用于系统地研究溶液/电极界面（例如，作为电极电位、溶液pH和表面官能度的函数）。具有关键化学官能团的模型有机化合物将被用作阐明催化电荷转移机制的探针，主要是在还原（阴极）条件下。此外，将并行进行一系列间歇反应实验，以确定这些还原转化的动力学，包括作为温度函数的测量，以确定活化能。实验数据将与密度泛函理论（DFT）计算相补充，以增强和验证机理的见解。原位ATR-FTIR光谱，动力学测量和DFT计算的组合将构成一种新的方法，用于开发更深入地了解在水溶液中的电化学反应的机制。这种新方法将使用导电掺硼金刚石（BDD）膜电极进行演示。BDD电极优于传统玻璃碳、贵金属和金属氧化物电极的主要优点是：1）在阳极极化下的高稳定性，2）抑制水电解反应，3）化学惰性，以及4）低背景电流和双层充电。这些性质也使BDD薄膜成为研究金属纳米粒子催化和电化学性能的理想载体。虽然近年来对BDD电极的研究有所增加，但在原位条件下对BDD表面和支撑的金属纳米颗粒的表面化学的机械理解尚未发展。BDD表面的表面化学可以根据所施加的电极电势和溶液条件而改变，并且是溶液/电极界面处的电荷转移的控制因素。这些因素决定了BDD电极在大量应用中的效用。更广泛的影响：BDD电极已经成功地显示出具有多种技术应用：1）水消毒和处理; 2）电化学传感;以及3）有机化合物的电合成。它们作为催化剂载体的潜在用途在很大程度上尚未开发，尽管它们的应用对于可能涉及水性环境的系统（例如用于燃料的生物原料加工或用于特种化学品生产的“绿色化学”）是非常有吸引力的。该项目还将增加代表性不足群体的研究生和本科生参与工程研究。研究生将参加阿尔弗雷德·P·斯隆基金会：美国印第安人研究生伙伴关系奖学金和亚利桑那州学者计划。该计划旨在满足全国对学术准备的美洲原住民的需求，他们可以帮助刺激社区和保留地的经济发展，并在学院和大学，政府和企业界占据领导地位。该项目还将提供新的扩展机会，通过UA高中毕业生专业实习计划，NASA太空补助本科生实习计划，UA水可持续性本科生奖学金计划和UA夏季研究所（SRI）让高中和本科生参与研究。化学与环境工程系目前是NSF REU和RET网站的主办方，该网站名为“可持续发展的系统方法：制造，水和能源”（NSF# 0649202）。拟议的研究将涉及几个本科生和高中教师从这些计划在每年的赠款。