Collaborative Research: Two-Dimensional Substrates to Study and Control the Atomic-Scale Structure of Metal Nanoclusters

含有有限数量的金属原子并附着在载体材料表面的纳米级簇（NC）在能源技术的应用中发挥着关键作用。 二维衬底提供了一个独特的平台来研究NC，由于其大而明确的表面，没有悬挂键，和最小的电子散射，这使得成像的NC原子分辨率。本研究的目标是采用自洽的，结合理论和实验的方法来研究支持的金属纳米粒子，以及这些如何适应基板的变化。理论计算基于经典和量子理论结合进化算法，而实验方法依赖于电子显微镜来确定纳米级的结构。在教育方面，拟议的研究将作为一个跨学科的平台，为研究生和本科生了解材料的发现在纳米级。鉴于新材料将对日常生活和国民经济产生重大影响，这项工作将通过开发新的课程内容和新的教育模块，加强匹兹堡大学和伊利诺伊大学芝加哥分校的材料教育，以及为大学预科生和高中生开展外展活动。技术概述三维（2D）基底是一个科学上具有挑战性的和很大程度上未开发的研究领域。完成后，这项工作将确定2D衬底的变化如何影响支持的NC的原子结构。的原子结构预测使用遗传算法，利用原子力场和密度泛函理论，然后使用像差校正的扫描透射电子显微镜进行验证。值得注意的是，将实验结果与理论预测相关联将导致对2D衬底上的支撑金属的基本理解的进步，这可能是使用这种衬底作为在原子尺度上控制金属簇结构的手段的基础。拟议的研究工作将进一步与教育工作相结合，研究生和本科生将接受多学科研究的培训。专门的努力和资源将用于招募和支持代表性不足的学生（妇女，非洲裔美国人，西班牙裔和第一代）在拟议的research.This奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Non Technical Summary Nanoscale clusters (NCs) containing a finite number of metal atoms and attached to the surfaces of support materials play a pivotal role for applications in energy technologies. Two-dimensional substrates offer a unique platform to study NCs owing to their large and well-defined surfaces with no dangling bonds, and minimal scattering of electrons, which allows for imaging of NCs with atomic resolution. The goal of this research is to employ a self-consistent, combined theoretical and experimental approach to study supported metal NCs, and how these adapt by substrate variations. The theoretical calculations are based on classical and quantum theories in conjunction with evolutionary algorithms, while as the experimental approach relies on electron microscopy to determine the structure at the nanoscale. Educationally, the proposed research will serve as an interdisciplinary platform for graduate and undergraduate students to learn about materials discovery at the nanoscale. Given the significant impact that novel materials will have on much of daily life and the national economy, this work will strengthen materials education at the University of Pittsburgh and the University of Illinois at Chicago via developing new course components and novel education modules, as well as conducting outreach activities for pre-college and high school students.Technical Summary The atomic structure of supported sub-nanometer clusters on two-dimensional (2D) substrates is a scientifically challenging and largely unexplored field of study. Upon completion, this work will determine how variations in 2D substrates can impact the atomic structure of supported NCs. The atomic structures are predicted using a genetic algorithm utilizing atomistic force fields and density functional theory, which are then validated using aberration-corrected scanning transmission electron microscopy. Significantly, correlating experimental results with theoretical predictions will lead to advances in the fundamental understanding of supported metals on 2D substrates that could be the basis for using such substrates as a means to control the structure of the metal clusters at the atomic scale. The proposed research efforts will be further integrated with educational efforts where graduate and undergraduate students will be trained in multidisciplinary research. Dedicated effort and resources will be used to recruit and support underrepresented students (women, African-Americans, Hispanics, and first-generation) in the proposed research.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.