Closing the solar fuel cycle: Investigating organic amines and water as reversible electron donors

关闭太阳能燃料循环：研究有机胺和水作为可逆电子供体

• 批准号: 1764353
• 负责人: Stefan Bernhard
• 金额: $ 49.54万
• 依托单位: Carnegie-Mellon University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1764353&HistoricalAwards=false
• 关键词: Closing; solar; fuel; cycle; Investigating

This award in the Catalysis program supports the work of Professor Stefan Bernhard at Carnegie Mellon University. This project focuses on the development of light rechargeable batteries as a cheap, practical way to capture and store the sun's energy for powering common electronic devices. The batteries are inspired by photosynthesis in plants which drives a fuel producing reaction called reduction via oxygen generation. For functional batteries to be produced, both of these types of reactions must be optimized and then combined with forward reactions representing charging, while the back reaction of the products serves as the discharge cycle. Possible reduction reactions targeted here produce hydrogen and metal products or compounds produced from carbon dioxide. To optimize the reduction, new catalysts and light absorbers are being designed to push the limits of performance and stability. On the oxidation side, the same kind of oxygen evolution in plants has already been widely studied, but here, work looks at a different chemistry, amine oxidation, as a potentially more practical alternative for use in a battery. This unexplored process can be established as a new tool for solar energy storage. Because this research project is aimed at a critical societal challenge, it inspires students to gain chemical knowledge and to become involved in chemical research. Moreover, the Bernhard laboratory continues to reach out to and involve researchers from underrepresented groups in the fields of science, technology and engineering. Educational activities at the undergraduate and graduate student level focus on the theme of renewable energy while outreach activities for non-scientists both educate the public on energy issues and instill excitement for science in general. Light to chemical energy conversion systems commonly comprise of a light-absorbing chromophore, a catalytic cycle producing reduced fuel, and a complementary oxidative cycle. Work proposed here aims to optimize these elements for unification in a solar rechargeable battery which can serve as a cheap, practical means of simultaneously capturing and storing the sun's energy. Such batteries would charge through solar driven forward reduction and oxidation while back reaction of the products would enable discharge. Work towards new batteries builds upon previous efforts in the Bernhard lab which have pioneered the use of Ir(III)-based chromophores as highly efficient drivers for photo-induced water and metal ion reduction. In the established schemes, these chromophores pass excited electrons to a reduction catalyst or substrate while receiving electrons from a sacrificial amine. This amine then undergoes irreversible C-N bond dissociation prohibiting any back electron transfer. However, translating this system to a rechargeable battery means that the amine donor must be designed to not suffer oxidation-induced degradation while still preventing back reaction. To this end, amines are being pursued with reversible electrochemistry as well as an oxidized form which is heavily stabilized via deprotonation and aromatization for prevention of back electron transfer. Initial electrochemical studies on amines pinpoint promising structures with suitable oxidation potentials. Subsequent studies in a galvanic cell then insure that the stable oxidized form of the amines can be reduced back to their original structures. Champion donors are ultimately utilized in systems where their oxidation is unified with a photo-induced reduction reaction producing metal or hydrogen fuel. Nuclear magnetic resonance and Raman spectroscopy are used to carefully monitor the fate of the amine upon illumination. While ongoing efforts are largely focused on amine oxidation, water oxidation is still a desirable counterpart for reductions in solar fuel schemes. Thus, some work is aimed at developing families of Ir(III) catalysts for water oxidation. The oxygen product of this reaction is a strong oxidant, so catalysts are being designed specifically to resist ligand oxidation for a longer lifetime.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.

这个催化项目的奖项支持了卡内基梅隆大学Stefan Bernhard教授的工作。该项目的重点是开发轻型可充电电池，作为一种廉价、实用的方式来捕获和储存太阳能，为普通电子设备提供动力。这种电池的灵感来自于植物的光合作用，这种光合作用通过氧气的产生来驱动一种称为还原的燃料产生反应。对于要生产的功能电池，这两种类型的反应都必须优化，然后与代表充电的正向反应相结合，而产物的反向反应则作为放电循环。此处所针对的可能的还原反应产生氢气和金属产物或由二氧化碳产生的化合物。为了优化还原，正在设计新的催化剂和光吸收剂，以推动性能和稳定性的极限。在氧化方面，植物中相同类型的氧气释放已经被广泛研究，但在这里，工作着眼于不同的化学，胺氧化，作为电池中使用的潜在更实用的替代品。这种未经探索的过程可以作为太阳能存储的新工具。 因为这个研究项目是针对一个关键的社会挑战，它激励学生获得化学知识，并成为参与化学研究。此外，伯恩哈德实验室继续接触和参与科学，技术和工程领域代表性不足的群体的研究人员。本科生和研究生一级的教育活动侧重于可再生能源的主题，而针对非科学家的外联活动既教育公众了解能源问题，又灌输对科学的普遍兴趣。光到化学能转换系统通常包括光吸收发色团、产生还原燃料的催化循环和补充氧化循环。这里提出的工作旨在优化这些元素，统一在太阳能充电电池，可以作为一个廉价，实用的手段，同时捕获和存储太阳能。这种电池将通过太阳能驱动的正向还原和氧化充电，而产物的反向反应将使放电成为可能。新电池的工作建立在伯恩哈德实验室先前的努力之上，该实验室率先使用Ir（III）基发色团作为光诱导水和金属离子还原的高效驱动剂。在已建立的方案中，这些发色团将激发的电子传递到还原催化剂或底物，同时从牺牲胺接收电子。然后，该胺发生不可逆的C-N键解离，阻止任何反向电子转移。然而，将该系统转化为可再充电电池意味着胺供体必须被设计为不遭受氧化诱导的降解，同时仍然防止逆反应。为此，胺正在用可逆电化学以及通过去质子化和芳构化高度稳定的氧化形式进行研究，以防止反向电子转移。对胺的初步电化学研究确定了具有合适氧化电位的有希望的结构。随后在原电池中的研究确保了胺的稳定氧化形式可以还原回其原始结构。冠军供体最终用于其中它们的氧化与产生金属或氢燃料的光诱导还原反应统一的系统中。核磁共振和拉曼光谱用于仔细监测胺在照射时的命运。虽然正在进行的努力主要集中在胺氧化，但水氧化仍然是减少太阳能燃料计划的理想对应物。因此，一些工作旨在开发用于水氧化的Ir（III）催化剂家族。该反应的氧产物是一种强氧化剂，因此催化剂被专门设计用于抵抗配体氧化，使其寿命更长。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

High-throughput Synthesis and Screening of Iridium(III) Photocatalysts for the Fast and Chemoselective Dehalogenation of Aryl Bromides

• DOI: 10.1021/acscatal.0c02247
• 发表时间: 2020-05
• 期刊: ACS Catalysis
• 影响因子: 12.9
• 作者: Velabo Mdluli;Stephen Diluzio;Jacqueline Lewis;Jakub F. Kowalewski;Timothy U. Connell;D. Yaron;T. Kowalew

High-Throughput Screening and Automated Data-Driven Analysis of the Triplet Photophysical Properties of Structurally Diverse, Heteroleptic Iridium(III) Complexes

• DOI: 10.1021/jacs.0c12290
• 发表时间: 2021-01-07
• 期刊: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
• 影响因子: 15
• 作者: DiLuzio, Stephen;Mdluli, Velabo;Bernhard, Stefan
• 通讯作者: Bernhard, Stefan

Parallelized Screening of Characterized and DFT-Modeled Bimetallic Colloidal Cocatalysts for Photocatalytic Hydrogen Evolution

• DOI: 10.1021/acscatal.9b05404
• 发表时间: 2020-04-03
• 期刊: ACS CATALYSIS
• 影响因子: 12.9
• 作者: Lopato, Eric M.;Eikey, Emily A.;Bernhard, Stefan
• 通讯作者: Bernhard, Stefan

High-throughput measurement of the influence of pH on hydrogen production from BaTiO3/TiO2 core/shell photocatalysts

• DOI: 10.1016/j.apcatb.2020.118750
• 发表时间: 2020-07
• 期刊: Applied Catalysis B-environmental
• 影响因子: 22.1
• 作者: Wenjia Song;Eric M. Lopato;S. Bernhard;P. Salvador;G. Rohrer

Bright Single-Layer Perovskite Host–Ionic Guest Light-Emitting Electrochemical Cells

• DOI: 10.1021/acs.chemmater.0c03934
• 发表时间: 2021-01
• 期刊: Chemistry of Materials
• 影响因子: 8.6
• 作者: Aditya Mishra;Stephen Diluzio;Masoud Alahbakhshi;Austen C. Adams;Melanie H. Bowler;Jiyoung Moon;Q. Gu-Q