Nanoscale Mapping and Manipulation of Activity on Single Catalytic Nanocrystals/Nanostructures

1263736陈、彭金属纳米粒子，包括异形金属纳米晶和等离子体纳米粒子，是新一代纳米催化剂，它们表现出各种类型的表面小面和位置。确定这些纳米粒子上的反应发生在哪里，以及哪些面和位置更活跃，包括在等离子体激发下，对于理解和开发优秀的纳米催化剂是至关重要的。国家科学基金会催化与生物催化计划授予纽约州伊萨卡市康奈尔大学的陈鹏教授的研究项目的长期目标是在亚粒子、纳米空间分辨率水平上了解金属纳米晶体催化剂和相关纳米结构的催化活性。单反应时间分辨率与催化剂颗粒形态、表面结构和等离子体性质相关。主要的方法是使用单分子超分辨催化成像，结合纳米级的物理、化学和等离子体操纵。一些预期的结果将增加这一实验计划的影响。首先，这些结果将有助于建立超分辨单分子荧光显微镜，作为一种强有力的新方法来考察纳米粒子和纳米结构在环境反应条件下的一次翻转时间分辨率和纳米空间分辨率的催化活性。其次，将确定金属纳米棒上的复杂反应模式及其结构基础。第三，探讨了表面等离子体增强催化对等离子体纳米结构的主导作用机理及其与催化增强的关系。这些预期成果有可能改变对纳米催化剂活性在空间和时间维度上的理解，导致新的和更好的纳米催化剂。该提案研究的更广泛的技术影响最终是它将提供基本的见解，有助于指导用于化学合成和能源应用的定形可控纳米晶体催化剂的应用和开发，以及用于更好地收集太阳能转化为化学能的等离子体纳米结构的应用和开发。计划中的外联、教育和培训活动将进一步加强教育战线上更广泛的影响，这些活动包括研究生和本科生以及K-12级学生。

1263736Chen, PengMetal nanoparticles, including shaped metal nanocrystals and plasmonic nanoparticles, are a new generation of nanocatalysts, and they exhibit various types of surface facets and sites. Determining where the reactions occur on these nanoparticles and which facets and sites are more active, including under plasmonic excitations, is essential for the understanding and development of superior nanocatalysts. The long-term goal of the research project awarded by the Catalysis & Biocatalysis Program of the National Science Foundation to Professor Peng Chen of Cornell University, Ithaca, NY is to understand the catalyt-ic activity of metal nanocrystal catalysts and related nanostructures at the sub-particle, nanometer spatial resolution level. Single-reaction time resolution is correlated with catalyst particle morphology, surface structure, and plasmonic properties. The main approach is to use single-molecule super-resolution catalysis imaging in combination with physical, chemical, and plasmonic manipulations at the nanometer scale.A number of expected outcomes will increase the impact of this experimental program. First, the re-sults will serve to establish the super-resolution single-molecule fluorescence microscopy as a powerful and novel way to interrogate the catalytic activity of nanoparticles and nanostructures at the single-turnover temporal resolution and nanometer spatial resolution under ambient reaction conditions. Second, the complex reactivity patterns and their structural basis on metal nanorods will be identified. And third, the dominant mechanisms of surface-plasmon-enhanced catalysis on plasmonic nanostructures and their correlation with catalytic enhancement will be explored. These expected outcomes have potential in trans-forming the understanding of nanocatalyst activity in both spatial and temporal dimensions, leading to new and better nanocatalysts.The broader technical impact of the proposal research is ultimately that it will offer fundamental in-sights that will help guide the application and development of shaped-controlled nanocrystal catalysts for chemical synthesis and energy applications, as well as of plasmonic nanostructures for better harvesting of solar energy for conversion to chemical energy. The broader impact will be further enhanced on the educational front by the planned outreach, education and training activities, encompassing graduate and undergraduate students and K-12 levels.