CAREER: Probing Oxygen-Mediated Electrochemical Processes of Oxides at High Spatial and Temporal Resolution

非技术描述：固体氧化物燃料电池-直接从燃料氧化产生电能的装置-被认为是清洁和高效的能源转换途径。由于这些器件的性能在很大程度上取决于空气电极上发生的氧基电化学反应的动力学，因此人们已经做出了巨大的努力来改善电极的性能，并从根本上更好地理解它。虽然反应的每个基本过程本质上都是由局部材料属性和几何形状决定的纳米级现象，但电化学性质主要是通过整体(体积平均)测量来分析的。为了在电极设计上取得突破，需要在纳米尺度上更彻底地了解这一过程。该项目旨在通过一种新型扫描探针显微镜类型的仪器进行原位纳米级观察，以期对电化学反应有新的见解。该项目正在培训本科生和研究生(包括代表不足的少数族裔学生)，为他们未来在能源技术部门就业做准备。技术细节：氧还原/析氧反应动力学(ORR/OER)对固体氧化物燃料电池和电解槽的性能有很大影响。虽然人们已经做出了巨大的努力来了解这些反应的基础机制，但在反应过程中的纳米级过程在很大程度上是未知的。该项目旨在通过利用一种带有微型加热器的基于扫描探头的新型设置，通过原位纳米级观察来促进对ORR/OER过程的理解。这项研究有三个重要方面：1)展示了一种新的基于高温扫描探针的方法，用于在操作氧活动下原位纳米级表征电化学表面反应和电荷传输动力学；2)开创了热激活过程的新的时间分辨纳米级表征；3)提供了关于ORR/OER和相关纳米级电荷传输的更深层次的见解。该项目为研究生和本科生提供广泛的研究机会，通过将研究纳入研讨会和课程来改进课程，并通过校园工程服务学习促进来自中央山谷当地和周围农村社区的K-12学生的有效教育。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

NON-TECHNICAL DESCRIPTION: Solid oxide fuel cells - devices that produces electricity directly from oxidizing a fuel - are considered routes for clean and efficient energy conversion. Since the performance of these devices is largely determined by the kinetics of the oxygen-based electrochemical reaction occurring at the air electrode, intense efforts have been made to improve the electrode performance and better understand it on a fundamental level. While each elementary process of the reaction is intrinsically a nanoscale phenomenon dictated by local material properties and geometry, the electrochemical properties have been mostly analyzed through bulk (volume-averaged) measurements. To obtain a breakthrough in electrode design, a more thorough understanding of the process at the nanoscale is needed. This project aims for new insights about the electrochemical reactions through in situ nanoscale observations, which is enabled by a novel scanning probe microscopy type instrument. This project is training undergraduate and graduate researchers (including underrepresented minority students) for their future employment in the energy technology sector. TECHNICAL DETAILS: The performance of solid oxide fuel cells and electrolyzers are largely affected by the kinetics of oxygen reduction/evolution reactions (ORR/OER). While intense efforts have been made to understand the underpinning mechanisms of the reactions, nanoscale processes during the reaction are largely unknown. This project aims to advance the understanding of ORR/OER processes through in situ nanoscale observations by leveraging a novel scanning probe-based setup with a microscale heater. There are three significant aspects of this research: 1) demonstrating a new high temperature scanning probe-based approach for in situ nanoscale characterizations of electrochemical surface reaction and charge transport kinetics under operating oxygen activities; 2) pioneering a novel time-resolved nanoscale characterization of thermally-activated processes; 3) providing deeper insight regarding the ORR/OER and related charge transport at the nanoscale. The project provides extensive research opportunities for graduate and undergraduate students, enhances curricula by incorporating research into seminars and courses, and promotes effective education for K-12 students from the local and surrounding rural communities in the Central Valley through the on-campus Engineering Service Learning.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.