UNS:Predictive Ab Initio Dynamics in Zeolite Biofuel Production Catalysts: Towards More Gas and Less Coke

UNS：沸石生物燃料生产催化剂中的预测从头算动力学：争取更多的天然气和更少的焦炭

• 批准号: 1512442
• 负责人: Scott Auerbach
• 金额: $ 32.98万
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-15 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1512442&HistoricalAwards=false
• 关键词: UNS; Predictive; Ab; Initio; Dynamics

Auerbach (1512442) - The study involves theoretical calculations aimed at understanding the complex catalysis involved in converting biomass-derived organic compounds to liquid fuel precursors in the confined spaces of zeolites while avoiding deactivation due to coke formation. A novel theoretical approach will be employed that will be benchmarked against experimental data. The PI will also incorporate aspects of his research into educational and outreach programs including an immersive summer science experience for middle- and high-school girls.The proposal builds on recognition that selective conversion of biomass-derived organic species to longer-chain liquid fuel precursors and the undesired reaction to form coke, are both examples of carbon-carbon bond forming reactions, and thus amenable to theoretical methods that provide insight into fundamental mechanisms of carbon chain growth as affected by zeolite structure and chemical properties. Thus, the proposed work addresses both phenomena, but through a unique theoretical approach - "metadynamics in reverse" - by examining the more-straightforward carbon-carbon bond breaking process and appealing to microscopic reversibility to gain insight into the carbon addition reactions. To this end, the PI will employ and extend several aspects of computational catalysis developed in his lab (in collaboration with the software firm SCHROEDINGER) to obtain accurate energetics of carbon bond forming and breaking while incorporating effects of framework dynamics and long-range forces, all while keeping simulation times manageable. Specifically, the work will address how confinement effects in the zeolite cage influence the balance between the activation and condensation steps in aldol condensation. The theoretical predictions will be benchmarked against related experimental studies carried out by his collaborator, Paul Dauenhauer.The broader impact of the research is in the general insight it will provide on organic reactions in zeolite structures, especially the factors that control selectivity between condensation reactions to produce desired specific carbon-number products and unchecked carbon condensation to form coke. In addition to the direct insight into the aldol condensation process, the theoretical techniques that will be developed and refined should have broad applicability to reaction processes in the confined environment of zeolite cages. The PI has developed a strong education and outreach plan that incorporates aspects of his research while addressing studies showing that interest in science and math dwindles amongst girls during their middle-school years. He also directs an inter-disciplinary program for undergraduate students at U Mass Amherst that forms teams of students to address real-world scientific issues, especially those dealing with biomedicine and renewable energy.

奥尔巴赫（1512442）-该研究涉及理论计算，旨在了解在沸石的有限空间中将生物质衍生的有机化合物转化为液体燃料前体所涉及的复杂催化作用，同时避免由于焦炭形成而导致的失活。 将采用一种新的理论方法，将对实验数据进行基准测试。 PI还将把他的研究纳入教育和推广计划，包括为初中和高中女生提供沉浸式夏季科学体验。该提案建立在认识到生物质衍生的有机物种选择性转化为长链液体燃料前体和形成焦炭的不希望的反应都是碳-碳键形成反应的例子的基础上，因此适用于提供对受沸石结构和化学性质影响的碳链生长的基本机制的深入了解的理论方法。 因此，拟议的工作解决了这两种现象，但通过一种独特的理论方法-“反向元吸附”-通过检查更直接的碳-碳键断裂过程，并呼吁微观可逆性，以深入了解碳加成反应。 为此，PI将采用和扩展他的实验室开发的计算催化的几个方面（与软件公司SCHROEDINGER合作），以获得碳键形成和断裂的精确能量学，同时结合框架动力学和长程力的影响，同时保持模拟时间可控。 具体来说，这项工作将解决沸石笼中的限制效应如何影响羟醛缩合中活化和冷凝步骤之间的平衡。 理论预测将与他的合作者Paul Dauenhauer进行的相关实验研究进行基准测试。该研究的更广泛影响在于它将提供对沸石结构中有机反应的一般见解，特别是控制缩合反应之间选择性的因素，以产生所需的特定碳数产品和不受限制的碳缩合形成焦炭。 除了直接洞察到的羟醛缩合过程中，理论技术，将开发和完善，应具有广泛的适用性，在沸石笼的密闭环境中的反应过程。 PI制定了一个强有力的教育和推广计划，其中包括他的研究方面，同时解决研究表明，在中学期间，女孩对科学和数学的兴趣减少。 他还指导了一个跨学科的计划，为本科生在U马萨诸塞州阿默斯特，形成学生团队，以解决现实世界的科学问题，特别是那些处理生物医学和可再生能源。