Design and Synthesis of Metallic Nanoparticle Interfaces for Enhancing Thermal Stability and Catalytic Behavior

用于增强热稳定性和催化行为的金属纳米粒子界面的设计和合成

• 批准号: 1411210
• 负责人: Stephen Sofie
• 金额: $ 47.5万
• 依托单位: Montana State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-15 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1411210&HistoricalAwards=false
• 关键词: Design; Synthesis; Metallic; Nanoparticle; Interfaces

Non-Technical AbstractNano-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. Technical AbstractHigh 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.

纳米材料提供了新的机会，以加强技术上重要的过程，如控制污染物，重组先进的燃料来源，以及使清洁和有效的能源转换。 然而，由于高颗粒迁移率和烧结过程，高温应用可能限制纳米材料的实用性。 在材料研究部门的固态和材料化学计划的支持下，该项目通过将金属纳米颗粒固定到具有新工程材料的陶瓷基底上，解决了高温颗粒不稳定性和纳米颗粒催化活性的不相容性。 这些材料的尺寸也是纳米级的，被设计成用作单个纳米颗粒和下面的基底之间的“胶水”或锚。 该活动将工程，化学和材料科学联系起来，提供了一个多学科的研究环境，为研究生和本科生解决材料科学，表面化学和催化领域的复杂问题做好准备。 高温非均相催化剂在废气治理、燃料重整、电化学能量储存和转换等方面起着至关重要的作用。 由于原子迁移和颗粒表面积的减小，高表面积金属纳米颗粒的热力学不稳定性限制了它们在高温下的使用。 密歇根州立大学的研究小组正在研究增强金属纳米颗粒的新方法，以利用广泛认可的金属催化性能，而不会牺牲纳米组件在高温下的稳定性。 研究目标正在通过设计新的界面相来实现，以化学方式将纳米颗粒结合到陶瓷载体上，从而在不影响催化活性的情况下实现所需的功能。 该项目的成果包括：i）优化方法，以定制锚定相的组成和位置; ii）确定负责实现锚定化学反应的机制; iii）评估机制对热，化学和电化学条件的敏感性; iv）确定锚定物赋予的效果，以在高达800摄氏度的高温下保持催化功能。 该研究活动的重点是将镍金属纳米颗粒锚定到离子导电陶瓷基底上，其中应用了第二相前体的金属有机溶液，并针对需要高和低纳米颗粒负载的特定催化剂功能进行了优化。 为了确定促进这种锚定策略的原子尺度机制，一套非原位和原位技术被用来解决相组成，材料的空间相关性，材料的稳定性，以及与二次相形成和颗粒粗化相关的反应动力学。该研究项目强调旨在抑制与表面扩散相关的金属传输的表面化学。 此外，研究小组正在利用机理分析将这些策略扩展到其他高温金属催化剂，包括那些需要贵金属的催化剂，其中在最低负载下提高性能至关重要。