Collaborative Research: Experimental and theoretical study on the structure and catalytic activity of metal cluster/metal oxide interfaces

合作研究：金属簇合物/金属氧化物界面的结构和催化活性的实验和理论研究

• 批准号: 1033000
• 负责人: Matthias Batzill
• 金额: $ 29.63万
• 依托单位: University of South Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1033000&HistoricalAwards=false
• 关键词: Collaborative; Research; Experimental; theoretical; study

1033000BatzillThe most successful metal/metal oxide catalysts currently available involve highly-dispersed, low-concentration metal atoms embedded in a metal oxide surface. Palladium metal supported on cerium oxide, is an important example of a highly active catalyst, with applications as an automotive three-way catalyst, in catalytic combustion, and as a solid oxide fuel cell anode material. The activity of these metal/metal oxide catalysts can be uniquely controlled by the support surface structure. Furthermore, these low-concentration metal catalysts have demonstrated significant resistance against sintering, a common multi-component catalyst degradation mechanism, thus indicating superior resistance to heating/cooling cycles and changes in redox enviroment. However, the structure of the active site is challenging to define at the atomistic scale. For the metal-ceria (M/CeO2) catalytic system, dynamic restructuring occurs under reaction conditions and both the ceria and metal structure alter reactivity. So how then to explain the catalytic and performance behaviors of Pd on ceria? Three Investigators, A.C. van Duin and M. J. Janik of Pennsylvania State University and M. M. Batzill of the University of South Florida, hypothesize that mixed surface oxides of Ce1-xPdxO2-d may provide unique active sites with high activity and stability under certain reaction conditions. To confirm this and in order to fully develop the potential of Pd/CeOx and similar metal/metal oxide catalysts, they believe a detailed, atomistic-scale knowledge of the catalytic conversion mechanisms and the surface dynamics related to substrate-surface interactions is required for the Pd/ceria system. In a collaborative study, the PIs propose to utilize atomistic simulation with Reactive Force-Field (ReaxFF) and Density Functional Theory (DFT) approaches together with experimental surface science studies to investigate the dynamic structure and reactivity of Pd/CeO2 systems. The combined surface science and ReaxFF/DFT approach will provide detailed determination of the structure, stability, and activity of Ce1-xPdxO2-?Ô?nmixed oxide surfaces. This will help answer questions about this catalyst system.From the broader perspective, the combination of experimental and computational approaches applied to this complex catalytic system will advance the fundamental understanding of the effect of reducible oxide supports on catalyst stability and activity, as well as provide guidance towards the preparation of highly active M/CeO2 catalysts. Further, the development of an integrated, two-component simulation environment, which is validated against experiment is the outcome of this project. This collaboration between simulation and experiment will provide a roadmap for future catalytic research; the computational tools developed here are generally applicable, thus providing straightforward extension to other catalytic materials.The research program also closely integrates education and outreach activities. Specifically, at PSU, courses for engineers on atomistic-scale simulation methods will be introduced, which will be complemented by lectures and tutorials on experimental techniques.

1033000 batzill目前可用的最成功的金属/金属氧化物催化剂涉及高度分散的低浓度金属原子，这些金属原子嵌入金属氧化物表面中。在氧化葡萄岩上支撑的钯金属是高度活性催化剂的一个重要例子，在催化混合物中用作汽车三向催化剂，以及作为固体氧化物燃料电池阳极材料。这些金属/金属氧化物催化剂的活性可以由支撑表面结构独特地控制。此外，这些低浓度的金属催化剂表现出对烧结的显着耐药性，这是一种常见的多组分催化剂降解机制，因此表明对加热/冷却周期和氧化还原环境中的变化具有较高的抵抗力。但是，活跃位点的结构要在原子量表上定义。对于金属谷（M/CEO2）催化系统，在反应条件下发生动态电阻，并且陶瓷和金属结构都改变了反应性。那么，如何解释PD上PD的催化和性能行为？宾夕法尼亚州立大学的A.C. A.C. Van Duin和M. J. Janik和南佛罗里达大学的M. M. Batzill假设CE1-XPDXO2-D的混合表面氧化物在某些反应条件下可能提供具有高活动性和稳定性的独特活性地点。为了确认这一点并为了充分发展PD/CEOX和类似的金属/金属氧化物催化剂的潜力，他们认为PD/CERIA系统需要对催化转化机制的详细，原子级知识以及与底物表面相互作用相关的表面动力学。在一项协作研究中，PIS提出了使用反应力场（ReaxFF）和密度功能理论（DFT）以及实验表面科学研究的原子模拟的建议，以研究PD/CEO2系统的动态结构和反应性。表面科学和ReaxFF/DFT方法的组合将详细确定CE1-XPDXO2-？？nmixed氧化物表面的结构，稳定性和活性。这将有助于回答有关该催化剂系统的问题。从更广泛的角度来看，应用于该复杂催化系统的实验和计算方法的结合将促进对减少氧化物支持对催化剂稳定性和活性的影响的基本理解，并为高度活跃的M/CEO2催化剂提供指导。此外，该项目的结果是对实验进行验证的综合两组分模拟环境的开发。模拟与实验之间的这种合作将为未来的催化研究提供路线图；此处开发的计算工具通常适用，因此可以直接扩展到其他催化材料。该研究计划还密切整合了教育和外展活动。特别是在PSU，将引入工程师课程原子规模的仿真方法，该课程将通过讲座和实验技术的讲座完成。