CAREER: Transition Metal Chalcogenide Clusters: Preformed Building Blocks for Framework Materials

职业：过渡金属硫族化物簇：框架材料的预制构件

• 批准号: 2045390
• 负责人: Christopher Bejger
• 金额: $ 62.44万
• 依托单位: University of North Carolina at Charlotte
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-02-01 至 2026-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2045390&HistoricalAwards=false
• 关键词: CAREER; Transition; Metal; Chalcogenide; Clusters

NON-TECHNICAL SUMMARYBulk transition metal chalcogenides (TMCs), are important materials for energy storage, electronic devices, and catalysis. However, TMCs are typically synthesized at high temperatures and pressures or are isolated using exfoliation techniques. Traditional synthetic approaches to TMC materials lack precise structural control, thus limiting their ability to be rationally tuned for specific applications. With this CAREER project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, Prof. Christopher Bejger studies how nano-sized fragments of TMCs can be used as building blocks for multidimensional scaffolds with high surface areas, known as metal-organic frameworks (MOFs). MOFs offer robust stability, crystalline structures, and can be predictably synthesized. The resulting hybrid materials share features of both conventional, bulk TMCs and crystalline MOFs. Frameworks made from TMC units undergo multiple, reversible oxidation state changes. Thus, TMC-MOFs are relevant to the study of nanoelectronics and future charge storage devices. The design of these materials provides inspiration for an integrated education component. The PI plans and fabricates an interactive Nanoscale Science Pop Up Museum, influenced by the principles of molecular and materials design, in collaboration with Prof. Rachel Dickey at the UNC Charlotte School of Architecture. The PI and his architecture colleague also partner with the Charlotte Teachers Institute (CTI) to present a seminar series for Charlotte-Mecklenburg School (CMS) teachers titled "Design Matter(s)" and host both science and art educators in a Summer Research Experience for Teachers.TECHNICAL SUMMARYThis research project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, investigates a new class of redox-active metal-organic frameworks (MOFs) comprising transition metal chalcogenide (TMC) molecular clusters. TMC clusters exhibit rich electrochemical behavior and have a propensity to undergo reversible, multi-electron transfer events. However, their use in MOF chemistry is limited by a lack of suitable synthetic protocols. The Bejger research group uses phosphine ligands with ancillary functional groups to incorporate pre-formed, atomically defined, metal-sulfide units into multidimensional frameworks. Several strategies are explored to expand the stoichiometric and structural combinations of precursors of the general formula MxSy (M= Ni, Co, Mo, Fe). The composition, topology, and surface areas of the materials are tailored to control the arrangement and charge of redox-active clusters. TMC clusters have mixed-valence, delocalized, metal-chalcogen cores that provide structural integrity across oxidation states and serve as electron reservoirs. Select TMC-MOFs that undergo stable charge/discharge cycling are studied for energy storage applications. TMC-MOF cathodes that mediate bifunctional charging are investigated for use in lithium ion batteries. The educational component of this proposal aims to increase civic engagement with materials chemistry through the lens of architecture and design. A pop-up museum is designed and fabricated as a collaborative project with the UNC Charlotte School of Architecture. The educational plan is multifaceted to emphasize links between MOF topology, reticular synthesis, and architecture. The ideas presented in the museum concept are disseminated and developed into a curriculum for local teachers through a partnership with the Charlotte Teachers Institute (CTI).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.

非技术概述块状过渡金属硫属化物（TMC）是用于能量存储、电子器件和催化的重要材料。然而，TMC通常在高温和高压下合成或使用剥离技术分离。TMC材料的传统合成方法缺乏精确的结构控制，从而限制了它们针对特定应用进行合理调整的能力。通过这个由材料研究部的固态和材料化学计划支持的职业项目，Christopher Bejger教授研究了如何将纳米尺寸的TMC片段用作具有高表面积的多维支架的构建块，称为金属有机框架（MOF）。MOFs提供了强大的稳定性、晶体结构，并且可以可预测地合成。所得的混合材料具有常规的块状TMC和晶体MOF两者的特征。由TMC单元制成的框架经历多次可逆的氧化态变化。因此，TMC-MOFs与纳米电子学和未来电荷存储器件的研究有关。这些材料的设计为综合教育部分提供了灵感。PI计划和制作一个互动的纳米科学弹出博物馆，受分子和材料设计原理的影响，与建筑的夏洛特夏洛特学院的Rachel Dickey教授合作。PI和他的建筑同事还与夏洛特教师学院（CTI）合作，为夏洛特-梅克伦堡学校（CMS）的教师举办了一系列题为“设计问题”的研讨会，并为教师举办了一次暑期研究体验，接待了科学和艺术教育工作者。技术总结该研究项目由材料研究部的固态和材料化学项目支持，研究了一类新的氧化还原活性金属有机骨架（MOFs），其包含过渡金属硫族化物（TMC）分子簇。TMC团簇表现出丰富的电化学行为，并具有进行可逆的多电子转移事件的倾向。然而，它们在MOF化学中的使用受到缺乏合适的合成方案的限制。Bejger研究小组使用具有辅助官能团的膦配体将预先形成的原子定义的金属硫化物单元纳入多维框架。探索了几种策略来扩展通式MxSy（M= Ni，Co，Mo，Fe）的前体的化学计量和结构组合。材料的组成、拓扑结构和表面积被定制以控制氧化还原活性簇的排列和电荷。TMC团簇具有混合价、离域的金属硫族元素核，其提供跨氧化态的结构完整性并充当电子库。选择TMC-MOFs进行稳定的充电/放电循环的储能应用进行了研究。研究了介导双功能充电的TMC-MOF阴极用于锂离子电池。该提案的教育部分旨在通过建筑和设计的透镜增加公民对材料化学的参与。一个弹出式博物馆的设计和制造作为一个合作项目与夏洛特夏洛特建筑学院。教育计划是多方面的，强调MOF拓扑结构，网状合成和建筑之间的联系。通过与夏洛特教师学院（CTI）的合作，博物馆概念中提出的想法被传播并发展成为当地教师的课程。该奖项反映了NSF的法定使命，并被认为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来支持。