EAGER: Imaging of Element-Specific 3D Distribution Dynamics in Working Bimetallic Catalysts by in situ Anomalous Small-Angle X-Ray Scattering

EAGER：通过原位反常小角 X 射线散射对工作双金属催化剂中元素特定的 3D 分布动力学进行成像

• 批准号: 1838277
• 负责人: Yugang Sun
• 金额: $ 10万
• 依托单位: Temple University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1838277&HistoricalAwards=false
• 关键词: EAGER; Imaging; Element; Specific; 3D

With support from the Chemical Measurement and Imaging (CMI) Program and the Chemical Catalysis (CAT) Program in the Division of Chemistry, Professor Sun at Temple University is developing a real-time imaging tool to map the spatial distribution of chemical elements at atomic resolution based on x-ray scattering. He works closely with scientists at the synchrotron light sources at national laboratories to look for technical solution that could be used to provide new insights about the structure-activity relationship of catalysts during catalytic reactions. There is a significant risk to achieve the desired imaging resolution in real time and under operando conditions. However, if successful, the outcomes of Professor Sun's work could help to guide the design and synthesis of efficient catalysts, an important research area that could potentially lead to significant impacts in many industries, ranging from petroleum refineries to pharmaceutical discoveries to fuel cells. The use of the state-of-the-art large-scale facilities at national laboratories trains the students to become specialists in a significant area that is underrepresented in the typical chemist?s skill set. More broadly, performing this research educates students (with emphasis on underrepresented groups) with multidisciplinary knowledge and prepares the technical workforce for academic and industrial positions relevant to efficient catalysis. In synergy with the research and professional training, Professor Sun is committed to a range of education and outreach programs to work with local Community College students, students and teachers from urban/high need schools in the Philadelphia School District, as well as students participating in a newly awarded NSF-REU site program located at Temple University and the Temple TUteach program.The integration of small-angle X-ray scattering (SAXS) measurements with ab initio modeling and calculations results in a capability of determining three-dimensional (3D) geometry of uniform nanoparticles. This project is to develop an imaging protocol to enable the study of the element-specific evolution of 3D atom distributions in bimetallic nanoparticles catalysts, requiring two consecutive steps of development. First, an imaging protocol is developed to reconstruct 3D compositional distribution in nanoparticles with a mass discontinuity through ab initio modeling of SAXS patterns of porous and hollow nanoparticles. Second, the imaging protocol for nanoparticles with a mass discontinuity is applied to extract the element-specific 3D images from the element-specific anomalous SAXS (ASAXS) patterns of uniform bimetallic catalyst nanoparticles using ab initio modeling and calculations, so-called ASAXS imaging. Successful development of the ASAXS imaging protocol enables the development of in-situ ASAXS imaging technique by coupling with in-situ reactors and devices, benefiting the study on the time-resolved evolution of element-specific 3D distributions of metals in working bimetallic catalysts under operando conditions.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.

在天普大学化学系化学测量与成像（CMI）项目和化学催化（CAT）项目的支持下，孙教授正在开发一种基于x射线散射的实时成像工具，以原子分辨率绘制化学元素的空间分布。他与国家实验室同步加速器光源的科学家密切合作，寻找技术解决方案，可用于提供催化反应过程中催化剂结构-活性关系的新见解。在操作条件下实现实时所需的成像分辨率存在很大的风险。然而，如果成功的话，孙教授的工作成果可能有助于指导高效催化剂的设计和合成，这是一个重要的研究领域，可能会对许多行业产生重大影响，从石油炼制到制药发现再到燃料电池。国家实验室使用最先进的大型设施，培养学生成为一个重要领域的专家，而这个领域在典型的化学家中代表性不足。S技能组合。更广泛地说，进行这项研究教育学生（重点是代表性不足的群体）具有多学科知识，并为与高效催化相关的学术和工业职位准备技术劳动力。在研究和专业培训的协同作用下，孙教授致力于一系列教育和推广项目，与当地社区学院的学生、费城学区城市/高需求学校的学生和教师，以及参加天普大学新授予的NSF-REU现场项目和天普TUteach项目的学生一起工作。将小角度x射线散射（SAXS）测量与从头算建模和计算相结合，可以确定均匀纳米颗粒的三维几何形状。该项目旨在开发一种成像方案，以研究双金属纳米颗粒催化剂中三维原子分布的元素特异性演化，需要连续两个步骤的开发。首先，通过从头算模拟多孔和空心纳米颗粒的SAXS模式，开发了一种成像方案，以重建具有质量不连续的纳米颗粒中的三维成分分布。其次，应用具有质量不连续的纳米颗粒成像方案，通过从头算建模和计算，从均匀双金属催化剂纳米颗粒的元素特异性异常SAXS （ASAXS）模式中提取元素特异性3D图像，即所谓的ASAXS成像。ASAXS成像方案的成功开发使原位ASAXS成像技术的发展与原位反应器和装置相结合，有利于研究工作双金属催化剂中金属元素特定三维分布的时间分辨演化。该奖项反映了美国国家科学基金会的法定使命，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。