EAGER: Controlling active site arrangement in zeolites through OSDA charge distribution

沸石是一种重要的工业材料，可以将低价值分子（例如，原油中不需要的成分）转化为高价值分子，可用于运输燃料和塑料生产。它们高度有序的原子级结构使这些化学转化成为可能。控制特定元素在这些材料中的结合位置的能力将是变革性的，导致现有技术的改进，并可能实现新技术，例如将生物质转化为更高价值的产品。然而，目前这是不可能的。这个探索性研究的早期概念拨款（EAGER）提案试图通过制定设计标准来改变现状，以控制合成过程中结构中特定元素的放置。拟议的工作是这样设计的，以便能够迅速评估这一概念的变革潜力，即一种具有巨大潜在影响的低投资方法。如果成功，这将为科学界在原子水平上控制沸石和其他重要工业材料的性质提供一种新的方法。分子筛具有孔径离散、骨架组成可控、骨架外阳离子可交换等特点，在催化领域得到了广泛的应用。控制局部结构，尤其是对框架铝的空间排列的操纵，一直是研究界长期追求的目标。EAGER项目试图通过结合以下概念来解决这一挑战：1)有机结构导向剂（OSDA）的电荷分布；2)如何将OSDA掺入到沸石中来控制铝的排列，即控制活性位点的排列。拟议的工作计划将能够通过使用不同的osda来快速评估合成具有不同铝空间排列的成分相似的ZSM-12材料的可行性。基于OSDA电荷分布和对OSDA在沸石孔隙中如何堆积的了解来改变沸石框架中铝的空间排列的能力将是革命性的，并代表着“设计催化剂”的重要一步。除了分配给该项目的一名研究生外，一名本科生将协助该项目，从而接受沸石合成和表征方法的培训。该奖项反映了美国国家科学基金会的法定使命，并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。

Zeolites are an industrially important class of materials that enable the conversion of low value molecules, for example, the undesirable components of crude oil, into higher value molecules that can be used in transportation fuels and plastics production. Their highly ordered atomic-level structures are what enable these chemical conversions. The ability to control where specific elements are incorporated in these materials would be transformative, leading to improvements in existing technologies, and likely enable new ones such as converting biomass to higher value products. However, this is not currently possible. This EArly-concept Grant for Exploratory Research (EAGER) proposal seeks to change the status quo by developing design criteria to control placement of specific elements in the structure during synthesis. The proposed work is designed such that it will be possible to rapidly assess the transformative potential of the concept, i.e., a low-investment approach with large potential impact. If successful, this will give the scientific community a new approach to controlling the properties of zeolites and other industrially important materials at the atomic level. Zeolites are widely used in catalysis as a result of their discrete pore sizes, controllable framework compositions and exchangeable extra-framework cations. Controlling local structure, most notably the manipulation of the spatial arrangement of framework aluminum, has been a long-sought goal in the research community. The EAGER project seeks to solve this challenge by combining the concepts of using 1) the charge distribution of the organic structure-directing agent (OSDA) and 2) basic insights as to how the OSDA is incorporated in the as-made zeolite to control the arrangement of aluminum i.e., control the active site arrangement. The proposed work plan will enable rapid assessment of the feasibility synthesizing compositionally similar ZSM-12 materials that possess different spatial arrangements of aluminum by using different OSDAs. The ability to modify the spatial arrangement of aluminum in the zeolite framework based on the OSDA charge distribution and knowledge of how the OSDAs pack in the zeolite pores would be transformative, and represent a significant step towards ‘catalysts by design’. Aside from the primary graduate student assigned to the project, an undergraduate student will assist in the project, thus receiving training in zeolite synthesis and characterization methods.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.