Collaborative Research: Correlating Molecular Structure and Activity in Boron-containing ODH Catalysts

随着世界人口的增长，对由乙烯和丙烯等积木化学品制成的消费品的需求也在增加。该项目的重点是发现高能效催化剂，从天然气中生产这些化学积木，并最大限度地减少二氧化碳等有害副产品的产生。研究人员的初步研究表明，含硼催化剂具有非凡的前景，但需要更深层次的原子水平的了解，以进一步提高催化剂的性能和耐用性。该项目将利用新的催化剂合成方案、最先进的固态核磁共振成像和计算方法的组合来获得所需的原子水平的理解，并利用这种洞察力来设计改进的催化剂。这项研究将通过将我国巨大的页岩气资源高效转化为增值燃料和化学品的潜力，为美国的清洁能源安全提供支持。低碳烷烃的氧化脱氢(ODH)是生产重要化学构件的一种很有前途的替代方法。然而，尽管经过了几十年的研究，高选择性的催化剂仍然难以找到，因为过度氧化是一个简单的、热力学上有利的过程。主要研究小组最近的研究表明，含硼催化剂(hBN、BNNT、WB等)对低碳烷烃的ODH反应具有很高的选择性。对于丙烷脱氢反应，丙烯选择性高达80%，转化率高达20%，而最先进的氧化钒催化剂在丙烷转化率为10%时，丙烯选择性高达60%。鉴于最近发现了这类材料作为ODH催化剂，关于活性中心及其形成，有许多基本问题需要回答。我们将利用受控合成、最先进的固体核磁共振波谱和计算模型来深入了解催化活性中心(S)，并建立含硼脱氢催化剂的结构-性能关系。这项工作将有助于在分子水平上理解一个具有工业重要性的复杂问题。我们的多学科方法包括合成、SS核磁共振表征、催化测试和计算建模，将训练参与的学生使用来自不同领域的信息来开发复杂系统的详细图景。此外，这项工作的协作性将有助于学生成长为研究团队中富有成效的成员。除了目标反应，这项研究将对更广泛的催化社区具有价值，因为普遍的催化洞察力和为表征非均相材料而开发的方法。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。

As the world population grows, the demand for consumer goods, which are made from building-block chemicals such as ethylene and propylene, increases. The project focuses on discovery of energy-efficient catalysts for the production of these chemical building-blocks from natural gas with minimal generation of undesired by-products such as carbon dioxide. Preliminary studies by the investigators have shown exceptional promise of boron-containing catalysts, but deeper, atomic-level understanding is needed to further improve the catalyst performance and durability. The project will utilize a combination of new catalyst synthesis protocols, state-of-the-art solid-state nuclear magnetic resonance imaging, and computational methods to obtain the needed atomic-level understanding, and use that insight to design improved catalysts. The research will support U.S. clean-energy security through its potential for the efficient conversion of our nation's vast shale gas resources to value-added fuels and chemicals. Oxidative Dehydrogenation (ODH) of light alkanes is a promising alternative for the production of important chemical building blocks. However, despite decades of research, a highly selective catalyst has remained elusive, as over-oxidation is a facile and thermodynamically favored process. Recent studies by the lead investigator's group has demonstrated that boron-containing catalysts (hBN, BNNT, WB, among others) are highly selective catalysts for the ODH of light alkanes. For propane ODH, propylene selectivity as high as 80% can be obtained up to 20% conversion, compared to 60% propylene selectivity at 10% propane conversion for the state-of-the-art vanadium oxide-based catalyst. Given the recent discovery of this class of materials as ODH catalysts, there are many fundamental questions that need to be answered regarding the active sites and their formation. Controlled synthesis, state-of-the-art solid-state NMR (SSNMR) spectroscopy, and computational modelling will be utilized to gain insights into the catalytically active site(s) and build up a structure-performance relationship for boron-containing ODH catalysts. The work will contribute to a molecular-level understanding of a complex problem that is of industrial importance. Our multidisciplinary approach comprised of synthesis, SSNMR characterization, catalytic testing, and computational modelling will train the participating students to use information from a variety of fields to develop a detailed picture of a complex system. Additionally, the collaborative nature of this work will help the students grow as productive members of a research team. Beyond the targeted reactions, the study will be of value to the broader catalysis community because of the generalized catalytic insights and the methods developed for characterization of heterogeneous materials.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.