Advanced Time-Resolved Studies of the O-O Bond Formation Mechanisms: Interplay of the Metal and Ligand Redox Reactivity

O-O 键形成机制的高级时间分辨研究：金属和配体氧化还原反应性的相互作用

• 批准号: 1900476
• 负责人: Yulia Pushkar
• 金额: $ 45万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1900476&HistoricalAwards=false
• 关键词: Advanced; Time; Resolved; Studies; Bond

In this project supported by the Chemical Structure, Dynamic & Mechanism,B Program of the Chemistry Division, Professor Yulia Pushkar of the Department of Physics and Astronomy at Purdue University studies the time-resolved mechanism of dioxygen (O2) formation in artificial photosynthesis. In artificial photosynthesis, solar energy is converted into chemical energy through generation of the clean fuels hydrogen and oxygen, a process which requires rearrangement of chemical bonds. Fundamental understanding of this process is required for the development of new catalysts and devices which are able to mimic natural photosynthesis. The development of artificial photosynthesis and its large-scale implementation can address energy needs of modern society. This research lies at the interface of physics, chemistry and materials science, with results expected to impact diverse fields and contribute to fundamental science, education and national energy security. Planned research and educational activities are designed to increase participation of under-represented students from economically disadvantaged backgrounds, improve experiences of female students in STEM (Science, Technology, Engineering and Mathematics), enhance training of students via integration of research results into curricula and to deliver teaching modules to schools. Research in this project focuses on the complex multi-electron chemical process of artificial photosynthesis. A major project goal is to determine the structure, electronic configurations and dynamics of the critical intermediates involved in water oxidation. In this multi-scale approach, time-resolved techniques monitor the evolution of structure and electronic states in newly designed ruthenium catalysts, with a focus on the key mechanism of oxygen-oxygen bond formation and its dependence on ligand structure. The relationship between molecular structure and catalytic activity is tested by a combination of experiments and quantum-mechanical computational models. Experimental techniques in this study of in situ catalytic water oxidation are synchrotron-based X-ray spectroscopy, including X-ray absorption near edge structure (XANES), extended X-ray absorption fine structure (EXAFS), electron paramagnetic resonance (EPR) and multi-wavelength kinetic resonance Raman spectroscopy. These experimental techniques deliver information on the structure of the intermediates and their electronic configuration as they evolve during the catalytic process.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.

普渡大学物理与天文学系的Yulia Pushkar教授在化学部化学结构、动力学机制B计划资助的本项目中，研究了人工光合作用中分子氧（O2）形成的时间分辨机制。在人工光合作用中，太阳能通过产生清洁燃料氢和氧转化为化学能，这一过程需要化学键的重排。对这一过程的基本理解是开发能够模拟自然光合作用的新催化剂和装置所必需的。 人工光合作用的发展及其大规模实施可以解决现代社会的能源需求。该研究处于物理学，化学和材料科学的界面，其结果预计将影响不同领域，并为基础科学，教育和国家能源安全做出贡献。计划开展的研究和教育活动旨在提高经济上处于不利地位的学生的参与率，改善女生在科学、技术、工程和数学方面的经验，通过将研究成果纳入课程来加强对学生的培训，并向学校提供教学模块。本项目的研究重点是人工光合作用的复杂多电子化学过程。 一个主要的项目目标是确定水氧化过程中关键中间体的结构、电子构型和动力学。 在这种多尺度方法中，时间分辨技术监测新设计的钌催化剂的结构和电子态的演变，重点关注氧-氧键形成的关键机制及其对配体结构的依赖性。通过实验和量子力学计算模型相结合的方法来检验分子结构与催化活性之间的关系。本研究采用同步辐射X射线光谱技术，包括X射线吸收近边结构（XANES）、扩展X射线吸收精细结构（EXAFS）、电子顺磁共振（EPR）和多波长动力学共振拉曼光谱。这些实验技术提供了中间体的结构及其电子构型的信息，因为它们在催化过程中演变。该奖项反映了NSF的法定使命，并已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标准进行评估的支持。

项目成果

Characterization of the Fe V =O Complex in the Pathway of Water Oxidation

• DOI: 10.1002/ange.202003278
• 发表时间: 2020-05
• 期刊: Angewandte Chemie
• 作者: R. Ezhov;A. K. Ravari;Y. Pushkar

A Highly Reactive Chromium(V)–Oxo TAML Cation Radical Complex in Electron Transfer and Oxygen Atom Transfer Reactions

• DOI: 10.1021/acscatal.1c00079
• 发表时间: 2021-02
• 期刊: ACS Catalysis
• 影响因子: 12.9
• 作者: Young Hyun Hong;Yuri Jang;R. Ezhov;M. Seo;Yong‐Min Lee;B. Pandey;Seungwoo Hong;Y. Pushkar;S. Fukuzumi;W. Nam

An evolutionarily conserved iron-sulfur cluster underlies redox sensory function of the Chloroplast Sensor Kinase

• DOI: 10.1038/s42003-019-0728-4
• 发表时间: 2020-01-08
• 期刊: COMMUNICATIONS BIOLOGY
• 影响因子: 5.9
• 作者: Ibrahim, Iskander M.;Wu, Huan;Puthiyaveetil, Sujith
• 通讯作者: Puthiyaveetil, Sujith

Atomically Dispersed Iridium on Indium Tin Oxide Efficiently Catalyzes Water Oxidation

• DOI: 10.1021/acscentsci.0c00604
• 发表时间: 2020-07-22
• 期刊: ACS CENTRAL SCIENCE
• 影响因子: 18.2
• 作者: Lebedev, Dmitry;Ezhov, Roman;Coperet, Christophe
• 通讯作者: Coperet, Christophe