CAREER: Unlocking Reactivity-Based Separations of Olefins using Metal-Organic Frameworks

化学分离是指将混合物分离成单独的组分，对于塑料等商品的工业生产至关重要。仅在美国，分离就占能源消耗的15%。开发新的节能分离技术可以大大减少温室气体排放，提高化学工业的可持续性，并降低日常消费品的成本。传统上，分离是基于化学品的物理性质的差异进行的，例如它们的沸点。在这里，研究人员将开发海绵状材料，能够根据不同的反应性分离化学物质。这将使工业分离对一种组分的选择性比另一种组分高得多，并可能开启新的分离类型。该项目将是高度跨学科的，涉及化学，化学工程和材料科学方面，这将有助于加强这些领域之间的交流。此外，来自代表性不足社区的新科学家将接受培训，提高STEM劳动力的多样性。作为该项目的一部分，公众，特别是农村社区的贫困学生，将了解化学分离、可持续性和绿色技术的重要性。烯烃等不饱和分子是全球聚合物生产的关键组成部分。然而，聚合反应通常需要烯烃的超纯料流以有效地进行。目前，含有烯烃的混合物（包括烯烃/链烷烃或烯烃异构体的混合物）基于其物理性质的微小差异而被低效地分离。该项目旨在根据反应性而不是物理性质的差异来分离含有烯烃的混合物。具体而言，被称为金属有机框架（MOF）的多孔结晶材料将被设计成使得它们可以与烯烃进行可逆的环加成反应。这些新的MOF系统将允许以无与伦比的选择性进行分离，并以节能的方式生产超纯烯烃产物流。材料的设计策略是潜在的推广到涉及一系列的不饱和分子，包括二氧化碳的分离，反映了这种方法的多功能性。将使用气体吸附分析和穿透测量来评估该策略的分离效率。吸附剂的反应性将使用原位固态核磁共振、X射线衍射和红外光谱进行表征。这个跨学科研究项目将在化学家、化学工程师和材料科学家之间建立新的联系。该奖项反映了NSF的法定使命，并且通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Chemical separations, which involve partitioning a mixture of compounds into its individual components, are critical to the industrial production of commodities such as plastics. Separations account for 15% of energy consumption in the United States alone. The development of new energy-efficient separations could greatly reduce greenhouse gas emissions, improve the sustainability of the chemical industry, and decrease the cost of everyday consumer products. Traditionally, separations are carried out based on differences in the physical properties of chemicals, such as their boiling points. Here, the investigator will develop sponge-like materials capable of separating chemicals based on their differing reactivities. This will enable industrial separations with much higher selectivities for one component over another and potentially unlock new types of separations. This project will be highly interdisciplinary, involving aspects of chemistry, chemical engineering, and materials science, which will help strengthen communication between these fields. In addition, new scientists from underrepresented communities will be trained, improving the diversity of the STEM workforce. As part of the project, the public, especially underserved students in rural communities, will learn about the importance of chemical separations, sustainability, and green technologies.Unsaturated molecules such as olefins are critical building blocks for the global production of polymers. However, polymerization reactions typically require ultrapure streams of olefins to proceed efficiently. Currently, mixtures containing olefins (including mixtures of olefins/paraffins or olefin isomers) are inefficiently separated based on small differences in their physical properties. This project seeks to separate mixtures containing olefins based on differences in their reactivities rather than physical properties. Specifically, porous crystalline materials known as metal-organic frameworks (MOF) will be designed such that they can undergo reversible cycloaddition reactions with olefins. These novel MOF systems will allow for separations to be carried out with unparalleled selectivities and for the production of ultrapure olefin product streams in an energy-efficient manner. The materials design strategy is potentially generalizable to separations involving a range of unsaturated molecules, including carbon dioxide, reflecting the versatility of this approach. The separation efficiency of the strategy will be assessed using gas adsorption analysis and breakthrough measurements. The reactivity of the adsorbents will be characterized using in situ solid-state nuclear magnetic resonance, X-ray diffraction, and Infrared spectroscopy. This interdisciplinary research program will forge new connections between chemists, chemical engineers, and materials scientists.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.