SusChEM: Single Molecule Studies of Aldol Condensation on Heterogeneous Catalysts

SusChEM：多相催化剂上羟醛缩合的单分子研究

• 批准号: 1664664
• 负责人: Keith Hohn
• 金额: $ 45万
• 依托单位: Kansas State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1664664&HistoricalAwards=false
• 关键词: SusChEM; Single; Molecule; Studies; Aldol

Converting renewable biomass resources to fuels provides a way to meet society's growing energy demands sustainably without reliance on fossil fuels. However, the compounds most easily extracted from biomass are quite different from conventional hydrocarbons obtained from processing petroleum or shale. One major difference is that most biomass-derived compounds are smaller than hydrocarbon fuels, necessitating catalytic reactions to build larger molecules from the original compounds. In these reactions, the catalyst is a solid film comprising chemicals that aid the efficiency of the reaction, but are not themselves consumed in the reaction. Drs. Hohn and Higgins are studying one such reaction, aldol condensation, to understand what catalytic properties are best suited to this task. To accomplish this, they follow a light-emitting reaction occurring on a catalyst film that they create with a gradient of catalytic properties along the film surface. Observing which parts of the film emit the brightest light provides information on the types of catalytic sites that are most active and allows the team to design improved catalysts. Research results are being disseminated in several ways, including through presentations at scientific conferences and peer reviewed publications. Dr. Hohn is also incorporating research results into outreach activities for K-12 students, while Dr. Higgins is introducing research results into a textbook on microscopy and into a graduate-level chemistry class.With funding from the Chemical Catalysis Program of the Chemistry Division, Drs. Hohn and Higgins of Kansas State University are developing a fundamental understanding of the catalytic properties responsible for activity in aldol condensation. They are applying single molecule methods to simultaneously measure acid/base properties and aldol condensation activity on thin films incorporating gradients in acid/base site densities. With these measurements, they are correlating catalytic activity in aldol condensation with the strengths and densities of the acid/base sites. The team applies surface characterization methods, including x-ray photoelectron spectroscopy (XPS) and Raman mapping studies, to augment the single molecule characterization studies. In addition, Drs. Hohn and Higgins correlate catalytic activity in aldol condensation with acid/base site proximity by preparing films with acid and base sites mixed at the molecular level and films where acid and base sites are separated by macroscopic distances. Along with regular publication of the results in the peer reviewed literature and presentation at conferences, Dr. Hohn is incorporates aspects of the research into activities for outreach programs at Kansas State University to enhance the recruitment of students from under-represented groups into science and engineering, while Dr. Higgins is introducing selected results into a graduate-level course and a textbook on chemical microscopy.

将可再生生物质资源转化为燃料提供了一种在不依赖化石燃料的情况下可持续地满足社会不断增长的能源需求的方法。然而，最容易从生物质中提取的化合物与从加工石油或页岩中获得的常规烃完全不同。一个主要的区别是，大多数生物质衍生化合物比烃燃料小，需要催化反应从原始化合物中构建更大的分子。在这些反应中，催化剂是包含有助于反应效率的化学物质的固体膜，但其本身在反应中不被消耗。 Hohn和Higgins博士正在研究一种这样的反应，羟醛缩合，以了解什么样的催化性能最适合这项任务。为了实现这一点，它们遵循在催化剂膜上发生的发光反应，它们沿着膜表面沿着产生具有催化性质梯度的催化剂膜。观察薄膜的哪些部分发出最亮的光，可以提供最活跃的催化位点类型的信息，并允许团队设计改进的催化剂。研究成果正在以多种方式传播，包括通过在科学会议上的介绍和同行评审的出版物。Hohn博士还将研究成果纳入到面向K-12学生的推广活动中，Higgins博士则将研究成果引入到显微镜教科书和研究生化学课程中。在化学系化学催化项目的资助下，堪萨斯州立大学的Hohn博士和Higgins博士正在对羟醛缩合反应中催化性质的基本认识进行研究。他们正在应用单分子方法同时测量薄膜上的酸/碱性质和羟醛缩合活性，并在酸/碱位点密度中加入梯度。通过这些测量，他们将羟醛缩合中的催化活性与酸/碱位点的强度和密度相关联。该团队应用表面表征方法，包括X射线光电子能谱（XPS）和拉曼映射研究，以增强单分子表征研究。此外，Hohn和Higgins博士通过制备具有在分子水平上混合的酸和碱位点的膜以及其中酸和碱位点通过宏观距离分离的膜，将羟醛缩合中的催化活性与酸/碱位点邻近性相关联。沿着定期在同行评审文献中发表研究结果并在会议上发表演讲，Hohn博士将研究的各个方面纳入堪萨斯州立大学的推广计划活动中，以加强从代表性不足的群体中招收学生进入科学和工程，而Higgins博士正在将选定的结果引入研究生课程和化学显微镜教科书。

项目成果

Fluorescence spectroscopy studies of crossed aldol reactions: a reactive Nile red dye reveals catalyst-dependent product formation

• DOI: 10.1039/d0cy00806k
• 发表时间: 2020-08
• 期刊: Catalysis Science & Technology
• 影响因子: 5
• 作者: Judith Bautista-Gomez;A. Usman;Man Zhang;Ryan J. Rafferty;S. Bossmann;K. Hohn;D. Higgins