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Metal-Sensitive Functionalization and Self-Assembly of Bimetallic Nanocrystals

双金属纳米晶的金属敏感功能化和自组装

基本信息

批准号：
2002653
负责人：
Younan Xia
金额：
$ 45万
依托单位：
Georgia Tech Research Corporation
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2021
资助国家：
美国
起止时间：
2021-01-01 至 2024-12-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2002653&HistoricalAwards=false
关键词：
Metal Sensitive Functionalization Self Assembly

项目摘要

The Macromolecular, Supramolecular, and Nanochemistry Program in the Chemistry Division supports Professor Dong Qin and her group at the Georgia Institute of Technology to develop tiny crystals called bimetallic nanocrystals. Their bimetallic nanocrystals contain two metals whose chemical function and spatial position within the nanocrystals are precisely controlled. Metal nanocrystals play a vital role in enabling catalysis for energy conversion, environmental protection, and organic synthesis. Despite some success, it remains a daunting challenge to monitor the catalytic reactions in real time by spatially confining the reactants to the catalytic sites while detecting the final and intermediate products in situ. The research team addresses this challenge by developing bimetallic nanocrystals in which one of the metals can serve as a catalyst while the other can report the ‘chemical fingerprint’ (signals associated with the reaction). The concepts, materials, and methods developed during this research may find use in a broad range of applications related to solid-state chemistry, catalysis, sensing, and photonics. This team recruits women and minority students as well as those from community colleges and minority institutions for summer research. This effort is carried out in collaboration with the National Nanotechnology Coordinated Infrastructure called the Southeastern Nanotechnology Infrastructure Corridor. In this research supported by the Macromolecular, Supramolecular and Nanochemistry (MSN) Program, Professor Qin’s team develops new design principles and methods to fabricate a novel class of bifunctional nanoreactors from Ag@M (M: Pt, Pd, and Rh) core-frame nanocubes via metal-selective surface functionalization and self-assembly. Specifically, molecules bearing isocyanide groups at the two ends are used to selectively bind to the M atoms on the edges of the core-frame nanocubes, serving as “clips” to bring two nanocubes face to face for the generation of a dimer. The gap region between the two nanocubes naturally presents a well-controlled nanoreactor, in which the side faces can be orthogonally functionalized with the reactants while the M atoms not coordinated by isocyanide will serve as the catalyst. Due to a strong plasmonic coupling between the two Ag nanocubes separated by a gap of only a few nanometers, the nanoreactor offers a unique capability to monitor various types of important catalytic reactions by in situ SERS. The model reactions include the hydrogenation of nitroaromatics for the production of thermodynamically unfavorable products such as hydroxylamine and azo compounds, as well as the bond-selective hydrogenation of cinnamaldehyde, a catalytic reaction pivotal to the production of fragrance, agrochemical, and pharmaceutical compounds. This research not only enables real-time characterization of heterogeneous catalytic reactions but also sheds light on the rational design of new or improved catalyst materials.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.

化学系的大分子、超分子和纳米化学项目支持佐治亚理工学院的秦冬教授和她的团队开发被称为双金属纳米晶体的微小晶体。它们的双金属纳米晶包含两种金属，它们的化学功能和在纳米晶中的空间位置是精确控制的。金属纳米晶在能源转化、环境保护和有机合成等方面起着至关重要的作用。尽管取得了一些成功，但通过在空间上将反应物限制在催化位置，同时原位检测最终和中间产物，实时监测催化反应仍然是一个艰巨的挑战。研究小组通过开发双金属纳米晶体来应对这一挑战，其中一种金属可以作为催化剂，而另一种金属可以报告“化学指纹”(与反应相关的信号)。在这项研究中开发的概念、材料和方法可能会在与固态化学、催化、传感和光子学相关的广泛应用中找到用途。这个团队招募妇女和少数民族学生以及来自社区大学和少数民族机构的学生进行暑期研究。这项工作是与被称为东南纳米技术基础设施走廊的国家纳米技术协调基础设施合作进行的。在这项研究中，秦教授的团队在大分子、超分子和纳米化学(MSN)计划的支持下，开发了新的设计原则和方法，通过金属选择性表面功能化和自组装，从Ag@M(M：Pt，Pd和Rh)核-骨架纳米立方体制备了一类新型的双功能纳米反应器。具体地说，在两端带有异氰基的分子被用来选择性地结合到核心-框架纳米立方体边缘的M原子上，作为夹子将两个纳米立方体面对面地产生二聚体。两个纳米立方体之间的空隙区域自然呈现出一个控制良好的纳米反应器，其中侧面可以与反应物正交功能化，而没有被异氰化物配位的M原子将作为催化剂。由于两个银纳米立方体之间的等离子体耦合很强，相隔只有几个纳米的间隙，该纳米反应器提供了一种独特的能力，通过原位SERS监测各种重要的催化反应。模型反应包括硝基芳烃的加氢反应，以生产热力学上不利的产物，如羟胺和偶氮化合物，以及肉桂醛的键选择加氢，这是一种对生产香料、农用化学品和药物化合物至关重要的催化反应。这项研究不仅能够对多相催化反应进行实时表征，还有助于合理设计新的或改进的催化剂材料。该奖项反映了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。