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

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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.