EFRI-PSBR: Continuous Liquid Fuel Production via Scalable Biosynthesis of Enzyme-Quantum Dot Hybrid Photocatalysts

EFRI-PSBR：通过酶-量子点混合光催化剂的可扩展生物合成连续生产液体燃料

• 批准号: 1332349
• 负责人: Steven McIntosh
• 金额: $ 200万
• 依托单位: Lehigh University
• 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: 2013-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1332349&HistoricalAwards=false
• 关键词: EFRI; PSBR; Continuous; Liquid; Fuel

ABSTRACTIntellectual Merit: The focus of this solicitation was to develop concepts for a photosynthetic biorefinery, in which micro-organisms are employed in the conversion of sunlight and carbon dioxide (CO2) to produce biofuel and bioproduct species. A systems approach is needed, and the system should be scalable. Life cycle analysis should be a tool used to evaluate various approaches. These components have been organized in an alternative manner in a project awarded jointly by the NSF Emerging Frontiers in Research and Innovation Division and the Catalysis and Biocatalysis Program of the CBET Division to the team of scientists and engineers of Professors Steven McIntosh, Bryan W. Berger, Robert Skibbens and Christopher J. Kiely of Lehigh University, Bethlehem, PA, and Ivan V. Korendovych of Syracuse University, Syracuse, NY. The investigative team proposes to create a novel bio-synthesized enzyme-quantum dot hybrid photocatalyst for the direct production of methanol fuel from sunlight, water, and carbon dioxide. The key components of this system include (1) quantum dots (QDs) as electron donors and (2) CO2-reducing enzymes for continuous conversion of CO2 and water to MeOH. Absorption of photons by QDs will generate electron-hole exciton pairs. The hole will be harnessed for water splitting to form protons, while the electron will be utilized as the energy source for the enzymatic CO2 reduction steps. This enzymatic process consumes the protons formed from water splitting, completing the catalytic cycle. Combining these two components (QDs and enzymes) in the proposed continuous flow process will create a cost-effective technology for the large-scale production of renewable liquid fuels.QDs will be synthesized using a unique bacterial system that facilitates precise control over particle size and corresponding wavelength range of the harvested light. In contrast to conventional, batch QD chemical synthesis, in which high temperatures, pressures and toxic solvents are required, the team approach allows for direct, extracellular production of water-soluble QDs directly from culture supernatants, with a target of reducing the cost of these materials by two orders of magnitude by removing the need for complex and expensive chemical processing steps, which is critical for achieving a cost-effective and scalable solution for direct liquid fuel production. A yeast-based system will be engineered to continuously generate the three enzymes that sequentially catalyze the reduction of carbon dioxide to methanol. Using a protein engineering approach, the PIs will modify these enzymes to self-assemble into a heterotrimeric complex on the surface of the quantum dot. These self-assembling enzyme catalysts overcome the current requirements for expensive precious metal based photocatalysts. Furthermore, the integrated enzyme-QD catalyst will achieve high selectivity for desired liquid fuel products by eliminating non-selective side reactions occurring with precious metal catalysts.Broader Impacts: Both scalable photocatalytic MeOH production and low cost QD fabrication offer significant long term impact on society and the US economy. A low cost, green fuel, produced continuously at commercial scale from carbon dioxide, sunlight, and water has obvious potential. The application of QD technology in information technology, lighting, and medicine is currently limited by the high cost of these specialized, crystalline nanomaterials. Reducing their production cost has the potential to foster new domestic industries. Likewise, the modular nature of the enzyme-QD hybrid nanocatalyst platform opens up new opportunities for scalable synthesis of other high-value chemical products from CO2 and sunlight.

摘要智力价值：本次征集的重点是开发光合生物精炼厂的概念，其中微生物被用来转化阳光和二氧化碳 (CO2)，以生产生物燃料和生物产品。需要一种系统方法，并且系统应该是可扩展的。生命周期分析应该是用于评估各种方法的工具。 这些组件以替代方式组织在一个项目中，该项目由 NSF 研究和创新部门新兴前沿以及 CBET 部门催化和生物催化计划联合授予 Steven McIntosh、Bryan W. Berger 教授的科学家和工程师团队，宾夕法尼亚州伯利恒理海大学的 Robert Skibbens 和 Christopher J. Kiely，以及纽约州锡拉丘兹锡拉丘兹大学的 Ivan V. Korendovych。研究小组提出创建一种新型生物合成酶-量子点混合光催化剂，用于从阳光、水和二氧化碳直接生产甲醇燃料。该系统的关键组件包括 (1) 作为电子供体的量子点 (QD) 和 (2) 用于将二氧化碳和水连续转化为甲醇的二氧化碳还原酶。量子点吸收光子将产生电子-空穴激子对。该空穴将被用于水分解形成质子，而电子将被用作酶促二氧化碳还原步骤的能源。该酶促过程消耗水分解形成的质子，完成催化循环。在拟议的连续流动工艺中将这两种成分（量子点和酶）结合起来，将为大规模生产可再生液体燃料创造一种具有成本效益的技术。量子点将使用独特的细菌系统合成，该系统有助于精确控制颗粒尺寸和所收集的光的相应波长范围。与需要高温、高压和有毒溶剂的传统批量量子点化学合成相比，该团队的方法允许直接从培养上清液中直接在细胞外生产水溶性量子点，目标是降低这些成本通过消除复杂且昂贵的化学加工步骤的需要，材料的数量增加了两个数量级，这对于实现直接液体燃料生产的具有成本效益和可扩展的解决方案至关重要。基于酵母的系统将被设计为连续产生三种酶，依次催化二氧化碳还原为甲醇。使用蛋白质工程方法，PI 将修饰这些酶，使其在量子点表面自组装成异源三聚体复合物。这些自组装酶催化剂克服了当前对昂贵的贵金属基光催化剂的要求。此外，集成酶-QD 催化剂将通过消除贵金属催化剂发生的非选择性副反应，实现所需液体燃料产品的高选择性。 更广泛的影响：可扩展的光催化 MeOH 生产和低成本 QD 制造都对社会产生重大的长期影响和美国经济。由二氧化碳、阳光和水以商业规模连续生产的低成本绿色燃料具有明显的潜力。目前，量子点技术在信息技术、照明和医学领域的应用受到这些专用晶体纳米材料的高成本的限制。降低生产成本有可能培育新的国内产业。同样，酶-QD混合纳米催化剂平台的模块化性质为利用二氧化碳和阳光大规模合成其他高价值化学产品开辟了新的机会。