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.

化学系的高分子、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称为双金属纳米晶体的微小晶体，他们的双金属纳米晶体含有两种金属，其化学功能和纳米晶体内的空间位置是精确的。尽管如此，金属纳米晶体在能量转换、环境保护和有机合成的催化方面发挥着至关重要的作用。尽管取得了一些成功，但通过将反应物空间限制在催化位点同时原位检测最终产物和中间产物来实时监测催化反应仍然是一项艰巨的挑战，研究小组通过开发双金属纳米晶体来解决这一挑战。金属可以充当催化剂，而另一种可以报告“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反应相关的广泛应用中得到应用。该团队招募女性和少数族裔学生以及来自社区大学和少数族裔机构的学生进行暑期研究，这项工作是与国家纳米技术协调基础设施（东南纳米技术）合作进行的。基础设施走廊。在这项由高分子、超分子和纳米化学（MSN）项目支持的研究中，秦教授的团队开发了新的设计原理和方法来制造新型双功能纳米反应器。通过金属选择性表面功能化和自组装，由Ag@M（M：Pt、Pd和Rh）核心框架纳米立方体制成。具体来说，两端带有异氰化物基团的分子被用来选择性地结合到Ag@M（M：Pt、Pd和Rh）核框架纳米立方体上核心框架纳米立方体的边缘，充当“夹子”，使两个纳米立方体面对面，以生成二聚体。两个纳米立方体之间的间隙区域自然地呈现出一个受控良好的纳米反应器。侧面可以与反应物正交功能化，而未与异氰化物配位的 M 原子将充当催化剂，由于两个仅几纳米间隙的银纳米立方体之间存在强等离子体耦合，因此纳米反应器提供了独特的功能。能够通过原位 SERS 监测各种类型的重要催化反应，模型反应包括硝基芳族化合物的氢化，用于生产热力学不利的产物，例如羟胺和偶氮化合物，以及肉桂醛的键选择性氢化，这是一种对香料、农用化学品和药物化合物生产至关重要的催化反应，这项研究不仅能够实时表征多相催化反应，而且还揭示了其合理性。新的或改进的催化剂材料的设计。该奖项反映了 NSF 的法定使命，并且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，被认为值得支持。