Current-Collector-Optional Measurements to Quantify Precious Metal and Polarization Impacts on Oxygen Surface Exchange Coefficients

电流收集器可选测量，用于量化贵金属和极化对氧表面交换系数的影响

• 批准号: 2241062
• 负责人: Jason Nicholas
• 金额: $ 49.71万
• 依托单位: Michigan State University
• 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: 2023-08-15 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2241062&HistoricalAwards=false
• 关键词: Current; Collector; Optional; Measurements; Quantify

Catalytic electrochemical devices are of increasing importance in alternative energy, environmental protection, and life-support technologies. The project focuses on a class of high-temperature devices including fuel cells, electrolyzers, oxygen generators, solar energy concentrators, and catalytic converters, that are often limited in performance by the slow exchange of oxygen with the surrounding atmosphere. Oxygen exchange is promoted by Mixed Ionic Electronic Conducting (MIEC) oxygen exchange catalysts. However, the identification of materials with improved oxygen exchange is presently limited by experimental artifacts associated with measuring the catalyst’s oxygen exchange rate (as typically characterized by a rate coefficient known as k(chem)). The project will quantify the sources of errors and lack of lab-to-lab reproducibility in traditional electrochemical k(chem) measurements, while demonstrating the effectiveness of a novel non-electrochemical thin-film method for accurately measuring oxygen exchange rates. Beyond the technical aspects, the project involves educational and outreach activities ranging from introducing 4-8th grade girls to engineering to teaching a course at the Michigan State Grandparent University Summer Camp. Recent experiments by the investigator’s group, and others, have demonstrated that precious metal current collectors, even unpolarized ones, can alter high-temperature MIEC k(chem) values. However, the full extent to which precious metal surface additions and/or electric polarization influence high-temperature MIEC k(chem) values, and the mechanisms by which this occurs, have yet to be fully explored. Hence, the objective of the project is to: 1) quantify the impact intentionally-added Pt surface additions and/or electric polarization have on the 400-600°C k(chem) of Pulsed Laser Deposited (PLD) praseodymium cerium oxide (PCO) thin films, 2) determine the mechanisms by which these fabrication and testing modifications alter the PCO k(chem), and 3) identify possible sources of previously-unrecognized, inadvertent precious metal contamination. This will be achieved by comparing the k(chem) values obtained from an in situ, non-contact, current-collector-optional wafer curvature measurement technique developed in the investigator’s group with those obtained via simultaneous Electrical Conductivity Relaxation and Electrochemical Impedance Spectroscopy. In addition, surface and bulk thin film composition and structural characterization techniques (such as X-Ray Diffractometry, Scanning Electron Microscopy, X-Ray Photoelectron Spectroscopy, and Secondary Ion Mass Spectrometry) will be used to identify relationships between k(chem) and materials properties.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.

催化电化学装置在替代能源、环境保护和生命支持技术中日益重要，该项目重点研究一类高温装置，包括燃料电池、电解槽、制氧机、太阳能聚光器和催化转换器。混合离子电子传导 (MIEC) 氧交换催化剂通常会导致其性能受到与周围大气缓慢交换的限制。目前受到与测量催化剂氧气交换率相关的实验工件的限制（通常以称为 k(chem) 的速率系数为特征）。该项目将量化传统电化学 k 中的误差来源和实验室间再现性的缺乏。 （化学）测量，同时展示了一种新型非电化学薄膜方法精确测量氧气交换率的有效性，除了技术方面之外，该项目还涉及教育推广和活动，包括向 4-8 年级女孩介绍工程和教学。密歇根州立大学的课程祖父母大学夏令营。研究小组和其他人最近的实验表明，贵金属集流体，即使是非极化的，也可以改变高温 MIEC k(chem) 值。然而，贵金属表面添加的全部程度。和/或电极化影响高温 MIEC k(chem) 值，以及其发生的机制尚未得到充分探索。因此，该项目的目标是：1) 量化有意添加的 Pt 的影响。表面添加和/或电极化对脉冲激光沉积 (PLD) 氧化镨铈 (PCO) 薄膜的 400-600°C k(chem) 产生影响，2) 确定这些制造和测试修改改变 PCO 的机制k(chem) 和 3) 识别先前未识别的、无意的贵金属污染的可能来源。这将通过比较获得的 k(chem) 值来实现。来自研究小组开发的原位、非接触式、集流器可选的晶圆曲率测量技术，以及通过同步电导率弛豫和电化学阻抗谱获得的测量技术。此外，还包括表面和体薄膜成分和结构表征技术。例如 X 射线衍射、扫描电子显微镜、X 射线光电子能谱和二次离子质谱）将用于识别关系k（化学）和材料特性之间的关系。该奖项反映了 NSF 的法定使命，并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，被认为值得支持。