RII Track-4:NSF: Design of zeolite-encapsulated metal phthalocyanines catalysts enabled by insights from synchrotron-based X-ray techniques

RII Track-4：NSF：通过基于同步加速器的 X 射线技术的见解实现沸石封装金属酞菁催化剂的设计

• 批准号: 2327267
• 负责人: James Shogren-Harris
• 金额: $ 20.6万
• 依托单位: University of Alabama Tuscaloosa
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-01-01 至 2025-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2327267&HistoricalAwards=false
• 关键词: RII; Track; NSF; Design; zeolite; RII; Track; NSF; Design; zeolite

Heterogeneous catalysts are used in a wide range of industries, including the chemicals and automotive sectors, to enable reactions to proceed under milder conditions with higher selectivity towards desired products. These materials have complex structures that are difficult to define, and therefore difficult to further improve. In this project, model catalysts will be developed that have well defined structures, in order to determine which aspects of these materials are beneficial for catalysis. Using state-of-the-art X-ray techniques available only at a handful of laboratories in the world (known as synchrotrons), the research team will precisely determine the structures of these materials during reaction. These measurements are not possible in university laboratories. Through this project, a graduate student and a professor will gain expertise in performing these measurements and analyzing the resultant data, allowing the researchers to share their knowledge with diverse collaborators across the state of Alabama. Through those efforts, this project will increase access to synchrotron-based X-ray techniques for researchers in Alabama, allowing the state to be increasingly competitive in attracting federal funding and private investment in scientific research. This Research Infrastructure Improvement Track-4 EPSCoR Research Fellows project will provide a fellowship to an Assistant Professor and training for a graduate student at the University of Alabama Tuscaloosa. This work would be conducted in collaboration with researchers at the SLAC National Accelerator Laboratory.Development of structure function relationships necessary for rational design of heterogeneous catalysts requires detailed knowledge of the structure of inorganic solids at the atomic level, including of the electronic structures of metal atoms and the local connectivity between atoms as a function of process conditions. Laboratory-scale techniques can quantify the number of metal binding sites but cannot identify and quantify their structural features (oxidation states, coordination numbers, and metal-ligand bond distances) during reaction. The best technique for these measurements is operando synchrotron-based X-ray absorption spectroscopy (XAS), wherein quantitative XAS data are collected over a working catalyst while reaction rates are measured simultaneously. The project will develop a fundamental understanding of the structure of zeolite-encapsulated metal-phthalocyanine complexes (MPCs) and the chemistries they mediate by taking extended visits to the Stanford Synchrotron Radiation Lightsource (SSRL) at SLAC National Accelerator Laboratory (SLAC). Combining XAS with in situ wide angle x-ray scattering (WAXS) and infrared spectroscopy measurements allows monitoring of the structure of both the primary binding sites, the structure of the zeolitic pores that confine them, and the intermediates present during catalysis. The research team will gain expertise in XAS and WAXS by working with recognized experts in these techniques. The materials characterized in this proposal avoid heterogeneities in local configurations of primary binding sites that are unavoidable for many other zeolite-, doped-carbon-, and MOF-based catalysts. These catalysts will be more stable than analogous MPC complexes in solution, allowing for gas-phase chemistry over single-site catalysts. This will be the first use of faujasite zeolite encapsulated MPC complexes, to our knowledge, for gas-phase oxidation reactions with N2O, and thus the first measurements of in situ or operando XAS spectra of these catalysts during this reaction. By gaining an understanding of the structure and stability of these materials under reaction conditions, we will describe catalysis over heterogeneous single-atom complexes without distractions from variation in the local configuration of the primary binding sites and the pores that confine them.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.

异质催化剂在包括化学品和汽车领域在内的广泛行业中使用，以使反应能够在更温和的条件下对所需产品的选择性更高。这些材料具有难以定义的复杂结构，因此很难进一步改进。在该项目中，将开发具有明确定义结构的模型催化剂，以确定这些材料的哪些方面对催化有益。研究团队使用最新的X射线技术仅在世界上少数几个实验室（称为同步基因）上可用，研究团队将精确确定反应过程中这些材料的结构。在大学实验室中，这些测量是不可能的。通过该项目，研究生和教授将获得执行这些测量并分析结果数据的专业知识，从而使研究人员能够与阿拉巴马州的各种合作者分享他们的知识。通过这些努力，该项目将增加对阿拉巴马州研究人员的基于同步加速器的X射线技术的访问权限，从而使该州在吸引联邦资金和科学研究的私人投资方面越来越有竞争力。这项研究基础设施改进Track-4 Epscor Research Fellows项目将为阿拉巴马大学Tuscaloosa大学的研究生助理教授和培训提供奖学金。这项工作将与SLAC全国加速器实验室的研究人员合作进行。结构功能关系的开发与异质催化剂的合理设计所必需的关系需要详细了解原子水平上无机固体的结构，包括金属原子的电子结构以及ATOM之间的局部连通性，以及attom之间的局部连通性。在反应过程中，实验室规模的技术可以量化金属结合位点的数量，但无法识别和量化其结构特征（氧化状态，协调数和金属 - 配体键距）。这些测量结果的最佳技术是基于Operando同步加速器的X射线吸收光谱（XAS），其中定量XAS数据是通过工作催化剂收集的，同时测量反应速率。该项目将对沸石封装的金属 - 苯胺复合物（MPC）的结构产生基本了解，并通过在SLAC National Accelerator Laborator（SLAC）的斯坦福同步辐射照明仪（SSRL）进行扩展访问，通过对斯坦福同步辐射照明（SSRL）进行扩展访问来进行中介。将XAS与原位广角X射线散射（蜡）和红外光谱测量结合在一起，可以监测两个主要结合位点的结构，限制它们的沸石孔的结构以及在催化过程中存在的中间体。研究团队将通过与公认的这些技术专家合作，在XAS和蜡方面获得专业知识。该提案中特征的材料避免了主要结合位点的局部构型中的异质性，而这些原始结合位点的局部构型对于许多其他沸石，掺杂碳和基于MOF的催化剂是不可避免的。这些催化剂将比溶液中的类似MPC复合物更稳定，从而可以在单位催化剂上进行气相化学。据我们所知，这将是Faujasite Zeolite封装的MPC复合物，用于与N2O的气相氧化反应，因此在此反应过程中这些催化剂的原位或操作XAS光谱的首次测量。 By gaining an understanding of the structure and stability of these materials under reaction conditions, we will describe catalysis over heterogeneous single-atom complexes without distractions from variation in the local configuration of the primary binding sites and the pores that confine them.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.