SusChEM: Deep Photochemical Reduction of Carbon Dioxide to Methanol

SusChEM：二氧化碳深度光化学还原为甲醇

• 批准号: 1301332
• 负责人: Frederick MacDonnell
• 金额: $ 43.03万
• 依托单位: University of Texas at Arlington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1301332&HistoricalAwards=false
• 关键词: SusChEM; Deep; Photochemical; Reduction; Carbon

The NSF Chemical Catalysis Program supports the efforts of Professors Frederick M. MacDonnell and Norma S. Tacconi of the University of Texas at Arlington to develop a class of molecular photocatalysts designed to drive the reduction of carbon dioxide all the way to methanol. Energy derived from fossil fuels, while central to today's economy, is not a sustainable solution to global energy needs and has potentially severe environmental consequences upon continued use. Liquid transportation fuels derived from fossil fuels are difficult to replace, however solar technologies that efficiently convert carbon dioxide (a greenhouse gas) to liquid fuels (such as methanol), could directly address this problem. This research team is using well-established ruthenium polypyridyl complexes as chromophores because of their stability, tunability, and favorable photophysical properties. These molecules are coupled with pyridine-based catalysts to obtain a deep 6-electron reduction of the carbon dioxide to methanol. Notably, despite all the advances with carbon dioxide electro- and photo-reduction with homogeneous transition metal catalysts, reduction has been limited to the two-electron reduction products (carbon monoxide or formic acid) with deeper reduction to methanol or methane conspicuously absent. The well understood ruthenium chromophore is being used to provide proof-of-concept results that establish the reaction mechanism before chromophores based on organics dyes or more earth-abundant elements are utilized. Photocatalytic activity is being studied in both aqueous (as a function of pH) and non-aqueous environments, in the presence and absence of metallic surfaces, and with various electrolytes and neutral modifiers to promote the desired reaction. Photocatalyst function is screened and interrogated using custom designed photoreactors and their catalytic efficiency is optimized by determining quantum yield and catalytic turnover as a function of reaction conditions. The technical implications of this research may help develop a carbon-neutral fuel cycle and produce a liquid fuel that requires minimal infrastructure changes to adopt. This research falls under the "SusChEM" program as it utilizes non-petroleum based resources (i.e., carbon dioxide) to produce a liquid fuel (methanol). The investigators are actively involved in K-12 education through a number of outreach programs, most notably through the development and implementation of an externally-funded "Chemistry Magic Show" run through the Science Ambassadors program in the College of Science. Over 43,400 students have seen the "Chemistry Magic Show" since its inception in 2008.

美国国家科学基金会化学催化项目支持阿灵顿德克萨斯大学的弗雷德里克·m·麦克唐奈教授和诺玛·s·塔科尼教授开发一类分子光催化剂，旨在将二氧化碳一路还原为甲醇。来自化石燃料的能源虽然是当今经济的核心，但不是全球能源需求的可持续解决方案，如果继续使用，可能会造成严重的环境后果。从化石燃料中提取的液体运输燃料很难被取代，然而太阳能技术可以有效地将二氧化碳（一种温室气体）转化为液体燃料（如甲醇），可以直接解决这个问题。由于钌多吡啶配合物的稳定性、可调性和良好的光物理性质，该研究小组正在使用成熟的钌多吡啶配合物作为发色团。这些分子与基于吡啶的催化剂偶联，以获得二氧化碳的深度6电子还原为甲醇。值得注意的是，尽管使用均相过渡金属催化剂的二氧化碳电还原和光还原取得了所有进展，但还原仅限于双电子还原产物（一氧化碳或甲酸），而进一步还原为甲醇或甲烷的明显缺失。在利用基于有机染料或更丰富的地球元素的发色团之前，充分了解的钌发色团正在提供概念验证结果，以确定反应机制。目前正在研究光催化活性在水（作为pH的函数）和非水环境中，在存在和不存在金属表面的情况下，以及使用各种电解质和中性改性剂来促进所需的反应。使用定制设计的光反应器筛选和询问光催化剂的功能，并通过确定反应条件下的量子产率和催化转化率来优化其催化效率。这项研究的技术意义可能有助于开发碳中性燃料循环，并生产出一种液体燃料，这种燃料需要最小的基础设施改变。这项研究属于“SusChEM”计划，因为它利用非石油资源（即二氧化碳）来生产液体燃料（甲醇）。研究人员通过一系列推广项目积极参与K-12教育，最引人注目的是通过科学学院的科学大使项目开发和实施外部资助的“化学魔术表演”。自2008年举办以来，已有超过43,400名学生观看了“化学魔术表演”。