Understanding the Mechanism of C-X hydrogenolysis Catalyzed by Supported Metal Nanoparticles

了解负载型金属纳米粒子催化的C-X氢解机理

• 批准号: 2154819
• 负责人: Rachel Austin
• 金额: $ 52.41万
• 依托单位: Barnard College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2154819&HistoricalAwards=false
• 关键词: Understanding; Mechanism; hydrogenolysis; Catalyzed; Supported

With funding from the Chemical Catalysis Program of the Chemistry Division, Professors Austin of Barnard College, Frederick and Schwartz of University of Maine, and Grabow of University Houston will study how to catalytically reduce off carbon-halogen bonds. The work is of relevance to the chemistry of the environment. In particular, a number of modern pesticides contain such carbon-halogen (iodine, bromine, chlorine, or fluorine) bonds. These molecules have been designed in part because they are stable, but that stability can also becomes a liability at the end of the projected product life cycle. This collaborative team will use a range of approaches to learn how to selectively reductively remove the halogens from these molecules. The team will also study catalysts that can break these bonds to understand precisely how they carry out this important chemistry, and build computational models to design new catalysts of greater practicality. All of the members of the team are committed to diversifying the scientific workforce. The PIs will work to recruit women into science, and into this research team in particular, through a newly formed 4 + 1 program at Barnard College, that provides program participants with the opportunity to complete a master's degree in chemical engineering at Columbia University in just one year after completing their specialized undergraduate degree at Barnard College. The selected students will spend time in a chemical engineering lab at the University of Maine and a computational chemical engineering lab at the University of Houston, in addition to time working at Barnard College and in the materials characterization labs at Columbia University, so that they will learn all of the facets of this multidisciplinary effort.This research project will test several mechanistic hypotheses about the nature of aromatic C-X bond hydrogenolysis catalyzed by supported metal nanoparticles. Reaction rate data for C-X bond hydrogenolysis in aromatic compounds shows a surprising lack of sensitivity to the identity of X, implying that C-X bond breaking is not rate-determining. The team hypothesizes that surface chemistry plays a critical role in dehalogenation of halogenated aromatic compounds in ways that are very different from the chemistry for the analogous alkyl-X species. The collaborative team will study the detailed steps of C-X bond hydrogenolysis on systems of increasing complexity and use data from those studies to inform density functional theory (DFT) calculations and allow for the joint experimental/computational team to build micro-kinetic models.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.

在化学系化学催化项目的资助下，巴纳德学院的奥斯汀教授、缅因州大学的弗雷德里克和施瓦茨教授以及休斯顿大学的格拉博教授将研究如何催化还原碳卤键。这项工作与环境化学有关。特别是，许多现代杀虫剂含有这种碳-卤素（碘、溴、氯或氟）键。 这些分子的设计部分是因为它们是稳定的，但这种稳定性也可能在预计的产品生命周期结束时成为一种责任。 这个合作团队将使用一系列方法来学习如何选择性地还原去除这些分子中的卤素。 该团队还将研究可以打破这些键的催化剂，以准确了解它们如何进行这种重要的化学反应，并建立计算模型来设计更实用的新催化剂。该团队的所有成员都致力于使科学劳动力多样化。 PI将通过巴纳德学院新成立的4 + 1计划，努力招募女性进入科学领域，特别是进入这个研究团队，该计划为计划参与者提供机会，在巴纳德学院完成专业本科学位后，在短短一年内完成哥伦比亚大学的化学工程硕士学位。 被选中的学生将在缅因州大学的化学工程实验室和休斯顿大学的计算化学工程实验室工作，此外还将在巴纳德学院和哥伦比亚大学的材料表征实验室工作，因此，他们将学习这个多学科努力的所有方面。这个研究项目将测试几个关于芳香族C-负载型金属纳米粒子催化X键氢解。芳族化合物中C-X键氢解的反应速率数据显示出令人惊讶的对X的身份缺乏敏感性，这意味着C-X键断裂不是速率决定性的。该团队假设，表面化学在卤代芳香族化合物的脱卤中起着关键作用，其方式与类似的烷基-X物种的化学性质非常不同。 该合作团队将研究C-X键氢解在日益复杂的系统上的详细步骤，并使用这些研究的数据为密度泛函理论（DFT）计算提供信息，并允许联合实验/计算团队建立微观结构。该奖项反映了美国国家科学基金会的法定使命，并被认为是值得通过使用基金会的智力价值和更广泛的影响审查进行评估的支持的搜索.