RUI: The Role of Engineered Ligands in Putative Homogeneous Catalysis: Supporting a Homogeneous Catalyst or Modulating Nanoparticle Formation

将二氧化碳（CO2）转化为有用的化学物质的能力，以及在化学合成中使用空气中的氧气作为试剂的能力等新兴技术，都依赖于能够加快反应速率和控制形成产物（选择性）的催化剂。催化剂可以在化学反应中改变结构和性质。催化剂的初始状态是已知的，但是一般来说，对于催化剂在工作条件下如何随时间变化所知甚少。西华盛顿大学的Margaret Scheuermann教授在催化剂工作的同时，正在鉴定和研究催化剂的结构。由Scheuermann教授领导的团队正在使用现有的和新开发的技术来表征合成结构并了解它们的催化性能。这些发现对催化剂结构的作用和意义有了新的认识。参与该项目的本科生和硕士生正在培养研究技能，他们将在以后作为STEM劳动力的成员应用这些技能。在化学部化学结构、动力学和机理B （CSDM-B）项目的资助下，西华盛顿大学的Margaret Scheuermann教授正致力于确定纳米颗粒形成的假设均相催化系统，表征颗粒，并试图辨别颗粒是非活性分解产物，催化剂前/非循环物种，还是活性催化剂。这些研究主要集中在易于还原的晚期金属上，这些金属具有高度工程化的多齿配体，是已知的生物质脱氧、CO2氢化/甲酸脱氢和有氧氧化反应的预催化剂。除了采用既定的测试来识别和评估假定的均相催化中的纳米颗粒外，Scheuermann小组正在开发基于离心力和非反应性聚合物的新测试，以深入了解所观察到的催化是由溶液化学（分子物种或小簇），表面（散装固体或纳米颗粒），还是两者的结合来最好地解释。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。

Emerging technologies such as the ability to convert carbon dioxide (CO2) into useful chemicals and the ability to use oxygen from the air as a reagent in chemical synthesis rely on catalysts that can speed up reaction rates and control which products are formed (selectivity). Catalysts can change structure and properties during a chemical reaction. The initial state of the catalyst may be known however, in general, far less is known about how catalysts might change over time under working conditions. Professor Margaret Scheuermann of Western Washington University is identifying and investigating catalysts structure while the catalyst is working. The team led by Professor Scheuermann is using both existing and newly developed techniques to characterize the resultant structures and understand their catalytic properties. The findings are giving insight into the role and significance of catalyst structure. The undergraduates and masters level students participating in this project are developing research skills that they will apply later as members of the STEM workforce. With funding from the Chemical Structure, Dynamics, and Mechanisms B (CSDM-B) Program of the Chemistry Division, Professor Margaret Scheuermann of Western Washington University is working to identify putative homogeneous catalytic systems in which nanoparticles are formed, characterize the particles, and attempt to discern whether the particles are an inactive decomposition product, a pre-catalyst/off-cycle species, or an active catalyst. The studies are focused on easily reduced late metals with highly engineered polydentate ligands that are known precatalysts for biomass deoxygenation, CO2 hydrogenation/formate dehydrogenation, and aerobic oxidation reactions. In addition to employing established tests for identifying and assessing nanoparticles in putative homogeneous catalysis, the Scheuermann group is developing new tests based on centrifugal forces and non-reactive polymers to gain insight as to whether the observed catalysis is best explained by solution chemistry (molecular species or small clusters), surfaces (bulk solid or nanoparticles), or a combination of the two.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.