Predictive Multi-Scale Modeling of Base Catalysis in Functionalized Zeolites

功能化沸石碱催化的预测多尺度建模

• 批准号: 0553577
• 负责人: Scott Auerbach
• 金额: --
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-10-01 至 2010-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0553577&HistoricalAwards=false
• 关键词: Predictive; Multi; Scale; Modeling; Base

Proposal Title: Predictive Multi-Scale Modeling of Base Catalysis in Functionalized ZeolitesProposal Number: CTS-0553577Principal Investigator: Scott M AuerbachInstitution: University of Massachusetts AmherstThe coming paradigm shift from fossil fuels to biofuels - those derived from renewable biomass - requires significant research into new catalysts that selectively transform biomass to biofuels. Efficient biorefining requires shape-selective catalysts with strong basic sites, because of the significant oxygen content in biomass. Although standard zeolites contain weak base sites, functionalized zeolites offer strong base sites by replacing zeolite oxygens with bridging amine (NH) groups. Initial calculations conducted in the principal investigator's group suggest that base-catalyzed reactions are faster by a factor of 100,000 at room temperature by substituting amine groups into zeolites. As interest in amine-substituted zeolites continues to grow, several fundamental questions remain, which can be addressed by molecular modeling: What is the maximum basicity attainable by amine-substituted zeolites? How is catalytic activity in these functionalized zeolites influenced by ion exchange? This project will assess the relative base strengths of several zeolites (various frameworks and compositions) with and without amine substitution, by computing adsorption energies of various Lewis-acid guest molecules. Quantum chemical energy calculations will be performed on embedded clusters in collaboration with scientists at Gaussian, Inc. The research will establish convergence of these energy calculations by comparing 2-layer and 3-layer embeddings with fully periodic quantum calculations.The calculations conducted in this research project will provide performance estimates for a burgeoning class of new catalysts: amine-substituted zeolites. This will assist zeolite chemists in the design and fabrication of advanced catalysts for biorefining applications. The collaboration with experimentalist C. Grey will help validate the theoretical predictions, and the collaboration with Gaussian, Inc. will lead to benchmarked software for the entire catalysis community to use for modeling reactions in zeolites. The research will be disseminated widely, especially through high school lectures entitled "High Octane Computing." Undergraduates and graduate students will be recruited from under-represented groups through two NSF-funded University of Massachusetts organizations: the Louis Stokes Alliances for Minority Participation, and the Northeast Alliance for Graduate Education. The broadest technical impact of this research translates to energy: shape-selective basic zeolites are important for catalyzing the future of biofuels.

提案标题：预测性多尺度模拟功能化沸石中的碱催化作用提案编号：CTS-0553577主要研究者：Scott M Auerbach机构：马萨诸塞州阿默斯特大学即将到来的从化石燃料到生物燃料（来自可再生生物质）的范式转变需要对选择性地将生物质转化为生物燃料的新催化剂进行重大研究。 有效的生物精炼需要具有强碱性位点的形状选择性催化剂，因为生物质中含有大量的氧。 尽管标准沸石含有弱碱位点，但官能化沸石通过用桥接胺（NH）基团取代沸石氧而提供强碱位点。 主要研究人员小组进行的初步计算表明，通过将胺基取代到沸石中，碱催化反应在室温下快了10万倍。 随着人们对胺取代沸石的兴趣不断增长，仍然存在一些基本问题，这些问题可以通过分子模拟来解决：胺取代沸石可达到的最大碱度是多少？ 离子交换如何影响这些功能化沸石的催化活性？该项目将通过计算各种路易斯酸客体分子的吸附能，评估几种沸石（各种框架和组合物）的相对碱强度，包括胺取代和非胺取代。 量子化学能量计算将与高斯公司的科学家合作在嵌入式集群上进行。 该研究将通过比较2层和3层嵌入与全周期量子计算来建立这些能量计算的收敛性。在该研究项目中进行的计算将为新兴的一类新催化剂：胺取代沸石提供性能估计。 这将有助于沸石化学家设计和制造先进的催化剂，用于生物精炼应用。 与实验学家C.格雷将帮助验证理论预测，以及与高斯公司的合作。将为整个催化界提供基准软件，用于模拟沸石反应。这项研究将被广泛传播，特别是通过题为“高辛烷值计算”的高中讲座。“本科生和研究生将通过两个NSF资助的马萨诸塞州大学组织从代表性不足的群体中招募：路易斯·斯托克斯少数民族参与联盟和东北研究生教育联盟。 这项研究最广泛的技术影响转化为能源：形状选择性碱性沸石对于催化生物燃料的未来非常重要。