Noble-Metal Nanocrystals in Metastable Phases

在化学系高分子、超分子纳米化学项目的资助下，格鲁吉亚理工学院的夏佑南博士和威斯康星大学麦迪逊分校的马诺斯·马夫里卡基斯博士将进行控制纳米晶体中原子空间排列（即晶相或结构）的基础研究。这种控制可以提供一种通用的方法来定制金属纳米晶体的电子结构和催化性能，为开发先进的催化材料打开大门，这些材料是能量转换的关键，也是重要化学品和药物生产的关键。一个重要的目标是使贵金属的成本效益和可持续利用成为可能，贵金属是地壳中最稀缺的元素。该项目的多学科和协作性质为丰富所有参与者的教育和培训经验提供了一个自然的工具。该项目的成果将用于加强课堂教学，包括开发与化学和化学工程关键概念相关的演示（动画和实验）。调查人员将通过让妇女、服务不足群体的成员参与这项研究项目来促进高等教育的多样性。具体来说，夏佑南博士和马诺斯·马夫里卡基斯博士正在开发用于合成金属的胶体方法（例如，钌）纳米晶体，以及良好控制的形状或表面结构。这些纳米晶体可能为观察新现象、增强现有工艺和实现创新应用开辟了途径。 目前，由于缺乏对机理的理解，在亚稳相中合成金属纳米晶体的报道数量非常有限。通过实验研究和计算建模的整合，研究人员试图阐明合成中涉及的趋势和机制，努力建立可靠生产特定晶相的实验条件。 钌纳米晶体将被用作种子模板沉积其他贵金属的核壳纳米晶体具有新的亚稳晶体结构的简易合成。在结构-性质关系的背景下，研究人员将评估亚稳态纳米晶体对析氧和氧还原反应的催化活性。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With funding from the Macromolecular, Supramolecular & Nanochemistry Program of the Chemistry Division, Dr. Younan Xia of the Georgia Institute of Technology and Dr. Manos Mavrikakis of the University of Wisconsin-Madison will conduct fundamental research toward controlling the spatial arrangement (i.e. the crystal phase or structure) of atoms in nanocrystals. Such control could provide a versatile means of tailoring the electronic structure and catalytic properties of metal nanocrystals, opening the door to the development of advanced catalytic materials key to energy conversion and key for the production of important chemicals and pharmaceuticals. An important goal is to enable cost-effective and sustainable use of precious metals, some of the scarcest elements in the earth’s crust. The multi-disciplinary and collaborative nature of this project offers a natural vehicle to enrich the education and training experiences of all participants. The results from this project will be adapted to enhance classroom teaching, including the development of demonstrations (animations and experiments) related to key concepts in chemistry and chemical engineering. The investigators will promote diversity in higher education by engaging women, member of underserved groups in this research project. Specifically, Dr. Younan Xia and Dr. Manos Mavrikakis are developing colloidal methods for the synthesis of metal (e.g., ruthenium) nanocrystals in non-conventional, metastable crystal phases, together with well-controlled shapes or surface structures. These nanocrystals may open up avenues for observing new phenomena, enhancing existing processes, and enabling innovative applications. Currently, there are only a very limited number of reports on the synthesis of metal nanocrystals in metastable phases owing to the lack of a mechanistic understanding. Through an integration of experimental studies and computational modeling, the investigators seek to elucidate the trends and mechanisms involved in the synthesis, striving to establish experimental conditions for the reliable production of a specific crystal phase. The ruthenium nanocrystals will be used as seeds to template the deposition of other noble metals for the facile synthesis of core-shell nanocrystals featuring new, metastable crystal structures. In the context of structure-property relationships, the investigators will evaluate the catalytic activities of the metastable nanocrystals toward the oxygen evolution and oxygen reduction reactions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.