CAREER: Bifunctional and Bimetallic Single-Site Catalysts for Sustainable Synthesis

在化学部(CHE)的化学催化项目和材料研究部(DMR)的固态和材料化学项目的资助下，Dianne肖博士和她在华盛顿大学的研究小组将设计新的多相催化剂，使化学合成能够更可持续地进行，包括使用可再生原料和替代危险试剂。她的团队将探索多个金属中心和有机官能团如何协同工作，以催化单一成分单独无法实现的转化。肖博士还将参与多项外展和教育活动，旨在扩大STEM的参与和提高公众的科学素养。这些将包括与当地博物馆和组织合作开展外联活动，在大学层面设计新的探究式实验室和教育资源，以及创建一系列旨在向公众宣传能源和环境问题的科学讲座。在酶中，多种有机和无机官能团共同努力，降低激活障碍，提高反应速度。将这些生物启发的概念应用到新型多相催化剂的设计中，该项目将探索一种简单但通用的模板策略，用于在金属-有机骨架孔内精确定位多个官能团。目前将双金属和双功能中心连接到固体表面的方法存在活性中心不均匀、结构精度低和化学可调性差等问题。这些合成限制反过来又极大地限制了我们对这些结构基序在多相催化环境中的行为和反应的了解。我们建议的模板策略提供了一个机会来探索双金属和双功能活性中心的化学，并确定细微差别的催化剂结构-活性关系。例如，酸碱距离、pKa和结构柔性如何影响双功能羟醛缩合催化剂的活性和稳定性？同样，金属的同一性、核性和配基环境在促进双金属O2的活化和转移中扮演了什么角色？对这些问题的回答将有助于推动未来的缩合和氧化催化剂的发展，这些催化剂能够使废物有价化，并促进绿色化学原则。使用这些新的合成工具，肖博士将研究复杂的表面支撑的活性中心，包括用于生物质利用的双功能酸碱中心和用于有氧氧化催化的双金属物种。肖博士还将积极参与多个年龄段的STEM推广计划，从K-12到大学和老年人口。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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 both the Chemical Catalysis program in the Division of Chemistry (CHE) and the Solid State and Materials Chemistry program in the Division of Materials Research (DMR), Dr. Dianne Xiao and her research group at the University of Washington will design new heterogeneous catalysts that will enable more sustainable chemical synthesis, including the use of renewable feedstocks and the replacement of hazardous reagents. Her group will explore how multiple metal centers and organic functional groups can work together to catalyze transformations not achievable by a single component in isolation. Dr. Xiao will also be engaged in multiple outreach and educational activities aimed at broadening STEM participation and enhancing public scientific literacy. These will include developing outreach activities in partnership with local museums and organizations, designing new inquiry-based labs and educational resources at the college level, and creating a series of science lectures aimed at informing the public on energy and environmental issues.In enzymes, multiple organic and inorganic functional groups work together to lower activation barriers and enhance reaction rates. Applying these bioinspired concepts to the design of new heterogeneous catalysts, this project will explore a simple yet versatile templating strategy for precisely positioning multiple functional groups within metal–organic framework pores. Current approaches for tethering bimetallic and bifunctional sites to solid surfaces suffer from active site non-uniformity, low structural precision, and poor chemical tunability. These synthetic limitations have, in turn, greatly limited our knowledge of how these structural motifs behave and react in a heterogeneous catalysis context. Our proposed templating strategy provides an opportunity to explore the chemistry of bimetallic and bifunctional active sites and identify nuanced catalyst structure–activity relationships. For example, how do acid-base distance, pKa, and structural flexibility influence the activity and stability of bifunctional aldol condensation catalysts? Similarly, what roles do metal identity, nuclearity, and ligand environment play in facilitating bimetallic O2 activation and transfer? Answers to these questions will help inform the development of future condensation and oxidation catalysts that enable waste valorization and promote green chemistry principles. Using these new synthetic tools, Dr. Xiao will interrogate sophisticated surface-supported active sites, including bifunctional acid–base sites for biomass utilization and bimetallic species for aerobic oxidation catalysis. Dr. Xiao will also be actively engaged in STEM outreach programs across multiple age demographics, from K–12 to college and the older adult population.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.