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

化学分离涉及将化合物混合物分割成其单独的组分，这对塑料等大宗商品的工业生产至关重要。仅在美国，分离就占到了能源消耗的15%。开发新的节能分离器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，分离是根据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个组件比另一个组件具有更高的选择性，并有可能解锁新类型的分离。这个项目将是高度跨学科的，涉及化学、化学工程和材料科学的各个方面，这将有助于加强这些领域之间的沟通。此外，还将培训来自代表性不足社区的新科学家，提高STEM劳动力的多样性。作为该项目的一部分，公众，特别是农村社区中服务不足的学生，将了解化学分离、可持续性和绿色技术的重要性。不饱和分子，如烯烃，是全球聚合物生产的关键构件。然而，聚合反应通常需要超纯的烯烃流才能有效进行。目前，含有烯烃的混合物(包括烯烃/烷烃或烯烃异构体的混合物)由于其物理性质的微小差异而被低效地分离。该项目寻求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。具体地说，被称为金属-有机骨架(MOF)的多孔晶体材料将被设计成能够与烯烃进行可逆的环加成反应。这些新颖的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品流。材料设计策略潜在地可以推广到涉及包括二氧化碳在内的一系列不饱和分子的分离，反映了这种方法的多功能性。该策略的分离效率将通过气体吸附分析和突破性测量进行评估。用原位固体核磁共振、X射线衍射和红外光谱对吸附剂的反应性进行了表征。这一跨学科研究计划将在化学家、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，并通过使用基金会的智力优势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.