Non-Technical Abstract Nano-materials offer new opportunities to enhance technically important processes such as controlling pollutants, restructuring advanced fuel sources, as well as enabling clean and efficient energy conversion. High temperature applications, however, can limit the utility of nano-materials due to high particle mobility and sintering processes. With support from the Solid State and Materials Chemistry Program in the Division of Materials Resarch, this project addresses the incompatibility of high temperature particle instability and nano-particle catalytic activity by securing metallic nano-particles to ceramic substrates with newly engineered materials. These materials, also nano-scale in size, are designed to serve as "glue" or anchors between individual nano-particles and the underlying substrate. Linking engineering, chemistry, and materials science, this activity provides a multi-disciplinary research environment that is preparing graduate and undergraduate students to tackle complex problems in areas of materials science, surface chemistry, and catalysis.
High temperature, heterogeneous catalysts play a vital role in emissions remediation, fuel reformation, and electrochemical energy storage and conversion. The thermodynamic instability of high surface area metal nano-particles limits their use at elevated temperatures due to atom migration and reduction of particle surface area. The research team at MSU is investigating new approaches for enhancing metallic nano-particles to leverage the widely recognized catalytic performance of metals without sacrificing the stability of nano-assemblies at elevated temperatures. Research goals are being accomplished by engineering new interfacial phases to chemically bind nano-particles to ceramic supports to achieve desired functionality without compromising catalytic activity. The project outcomes include i) optimizing methods to tailor anchoring phase composition and location; ii) identifying the mechanisms responsible for enabling the anchoring chemical reactions; iii) evaluating the sensitivity of the mechanisms to thermal, chemical, and electrochemical conditions; and iv) identifying the effects conferred by anchors to preserve catalytic function at high temperature up to 800 Celsius. This research activity focuses on anchoring nickel metal nano-particles to ion conducting ceramic substrates in which metal-organic solutions of secondary phase precursors are being applied and optimized for specific catalyst functionality where both high and low nano-particle loading is required. To identify the atomic scale mechanisms that foster this anchoring strategy, a suite of ex-situ and in-situ techniques are being utilized to resolve phase compositions, spatial correlations of materials, material stability, and reaction kinetics associated with secondary phase formation and particle coarsening. The research project emphasizes surface chemistry designed to inhibit metal transport associated with surface diffusion. Further, the research team is utilizing the mechanistic analysis to expand these strategies to other high temperature metal catalysts including those requiring precious metals where enhancing performance at minimum loading is critical.
