Collaborative Research: On the Origin of Atomic Layer Deposition Enhanced Activity and Stability of Nanostructured Cathodes for Intermediate-temperature Solid Oxide Fuel Cells

非技术描述：在这个由材料研究部陶瓷项目支持的合作项目中，Kevin Huang教授和Xinhua Liang教授正在为中温固体氧化物燃料电池（it - sofc）开发高活性和稳定的纳米结构阴极。it - sofc是一种商业上可行的高效低排放动力产品，具有取代传统内燃机的巨大潜力。目前用于it - sofc的阴极是具有高催化活性的纳米结构，但不幸的是不稳定，在使用过程中逐渐失去活性。本项目的重点是通过原子层沉积（ALD）稳定纳米结构阴极，并了解ALD工艺显著增强纳米结构阴极稳定性和活性的原因。从该项目中获得的基本知识有望有助于理解催化界观察到的活性-稳定性困境，并在开发用于商用it - sofc的新型活性和稳定阴极方面发挥重要作用。该项目资助一名女研究生和一名少数民族本科生。技术细节：it - sofc成功的关键是开发高活性和稳定的阴极。目前的纳米结构活性阴极在高温下是不稳定的。该项目旨在开发活性和稳定的纳米结构阴极，并通过综合的“理论假设”和“实验验证”方法研究支持增强催化活性和稳定性的基础科学。研究了包含纳米孔隙度、混合氧化物离子和电子电导率、锶偏析抑制和形态稳定的多功能缺陷化学模型作为理论基础。一套先进的原位、操作和非原位表面分析技术被用于系统地探测化学和电子状态、表面/亚表面相和明确定义的外延异质结构的形态演变，以收集验证和/或修改模型的关键实验证据。电催化的电荷传输机制也被研究在图案化的电极薄膜结构上，以收集个性化的电化学性质，并将它们与表面化学结果联系起来。研究生和本科生，包括少数民族和其他代表性不足的群体成员，通过明确确定和重点研究项目，在这项研究中发挥积极作用。该项目的重要性和潜在影响正在通过南加州大学和密苏里大学的特别外展计划向公众传播。南加州大学正在为研究生开设一门新课程。与本尼迪克特学院（Benedict College）——一所历史悠久的黑人学院——建立了一个联合教育项目，旨在促进代表性不足的学生的教育和劳动力发展。

NON-TECHNICAL DESCRIPTION: In this collaborative project supported by the Ceramics Program in the Division of Materials Research, Professor Kevin Huang and Professor Xinhua Liang are developing highly active and stable nanostructured cathodes for intermediate-temperature solid oxide fuel cells (IT-SOFCs). IT-SOFCs are a commercially viable high-efficiency and low-emission power product with a great potential to replace conventional internal combustion engines. The current cathodes for IT-SOFCs are nanostructured with high catalytic activity, but are unfortunately unstable, gradually losing their activity during operation. This project focuses on stabilizing nanostructured cathodes with atomic layer deposition (ALD) and understanding the reason behind why stability and activity of nanostructured cathodes are significantly enhanced by the ALD process. The fundamental knowledge gained from this project is expected to contribute to the understanding of the activity-stability dilemma observed in the catalysis community and play a significant role in developing new active and stable cathodes for commercial IT-SOFCs. The project supports one female graduate student and one minority undergraduate student.TECHNICAL DETAILS: A key to the success of IT-SOFCs is to develop highly active and stable cathodes. The current nanostructured active cathodes are unstable at elevated temperatures. This project is aimed at developing active and stable nanostructured cathodes and investigating the fundamental science underpinning the enhanced catalytic activity and stability through an integrated "theoretical hypothesis" and "experimental validation" approach. A multifunctional defect-chemistry model entailing nanoscale porosity, mixed oxide-ionic and electronic conductivity, Sr-segregation suppression and morphological stabilization is being investigated as the theoretical basis. A suite of advanced in situ, in operando and ex situ surface analysis techniques is being utilized to systematically probe the profiles of chemical and electronic states and surface/sub-surface phase and morphology evolutions of well-defined epitaxial heterostructures to gather key experimental evidence for validating and/or modifying the model. The electrocatalytic charge-transport mechanisms are also being investigated on patterned electrode thin-film structures to collect the individualized electrochemical properties and correlate them with the surface chemistry results. Both graduate and undergraduate students including members of minority and other underrepresented groups play an active role in this research through clearly identified and focused research projects. The importance and potential impact of the project are being disseminated to the general public via special outreach programs at USC and Missouri S&T. A new course is being created for graduate students at USC. A joint educational program with Benedict College, a historically black college, has been previously established with the goal to promote education and workforce development for underrepresented students.