NSF-DFG Confine: Plasma-Catalysis in Confined Spaces for Cold Start NOx Abatement in Automotive Exhaust

NSF-DFG Confine：密闭空间中的等离子体催化用于冷启动汽车尾气中的氮氧化物减排

• 批准号: 2234270
• 负责人: Peter Bruggeman
• 金额: $ 60万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2025-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2234270&HistoricalAwards=false
• 关键词: NSF; DFG; Confine; Plasma; Catalysis

This project seeks to transform traditional chemical processing to ensure a sustainable future. Catalysis, which facilitates desired chemical reactions, has played a key role in defining the modern standard of pollution abatement, high-energy density fuels, and proficient and safe fuels and fertilizers. This project aims to develop an understanding of new concepts in the practice of chemical catalysis enabled by coupling of non-equilibrium plasma with surface catalyzed reactions. NOx abatement in capillary microreactors, mimicking “honeycomb monoliths” in modern-day catalytic converters, at near ambient temperatures serve as a testbed system. Tailpipe emissions in transportation account for a majority of NOx pollution harming human health and the environment. State-of-the-art automobile exhaust after-treatment systems remediate NOx efficiently above a threshold light-off temperature 473 K (200 degrees C), sufficient to overcome kinetic limitations inherent in catalytic processes. The project harnesses interactions among plasma chemistry and thermocatalytic processes in confined geometries to enable NOx reduction in automobiles at near ambient temperatures. This addresses “cold start” automotive emissions during engine warm up, which account for 80% of NOx vehicular pollution. This project furthers US-German scientific collaboration and training in STEM.Plasma chemistry occurs volumetrically and involves short-lived reactive intermediates—ions, radicals, electronically- and vibrationally-excited species—which when impinged on a selective catalytic surface could effect chemical transformations and pathways inaccessible to conventional catalysis. The disparity in reaction timescales of plasma (sub-10^-6 to 10 s) and catalytic chemistry (10^-1 to 10 s) and the different length scales for plasma (volume) and catalytic (surface) chemistry implies that effective coupling between plasma and surface catalytic chemistry can only be achieved if surface-to-volume ratios are large to enable a high flux of short-lived plasma-derived intermediates to the catalyst surface. Hence, confinement, enabling very high surface-to-volume ratios, is key to coupling volumetric and fast plasma chemistry with selective, slower surface-based catalytic processes. The project combines reactor design, advanced spectroscopic and spectrometric diagnostics, and multiscale modeling to examine reaction and transport phenomena impacting plasma-catalytic chemistry coupling in confined reaction environments. This includes (1) probing characteristic diffusion time scales and lifetimes of reactive species in combined operation of plasma- and thermocatalytic processes within capillary microreactors, (2) developing spectroscopic and spectrometric tools to identify and enumerate short-lived reactive intermediates in the gas phase and on catalyst surfaces and (3) developing multiscale models describing the underpinning processes in these confined reaction environments. This will allow to elucidate how reaction and transport phenomena impact plasma-catalytical coupling and describe new catalytic species and pathways for NOx reduction. This project was awarded through the “Chemistry and Transport in Confined Spaces (NSF-DFG Confine)" opportunity, a collaborative solicitation that involves the National Science Foundation and Deutsche Forschungsgemeinschaft (DFG).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.

该项目旨在改变传统的化学加工，以确保可持续的未来，促进所需的化学反应，在定义污染减排、高能量密度燃料以及高效和安全的燃料和肥料的现代标准方面发挥了关键作用。该项目旨在通过将非平衡等离子体与毛细管微反应器中的表面催化反应耦合来实现化学催化实践中的新概念，模仿“蜂窝”。现代催化转化器中的“整体式”，在接近环境温度下作为测试平台系统，运输中的尾气排放占危害人类健康和环境的氮氧化物污染的大部分。在高于 473 K（200 摄氏度）的阈值起燃温度下有效修复 NOx，足以克服催化过程固有的动力学限制。该项目利用等离子体化学和热催化过程之间的相互作用。几何形状可在接近环境温度下减少汽车中的氮氧化物 这解决了发动机预热期间的“冷启动”汽车排放问题，该排放占氮氧化物车辆污染的 80%。体积发生并涉及短暂的中间反应物——离子、自由基、电子和振动激发的物质——当它们撞击选择性催化表面时可能会影响化学转化和途径等离子体（亚10^-6至10秒）和催化化学（10^-1至10秒）的反应时间尺度的差异以及等离子体（体积）和催化（表面）的不同长度尺度。化学意味着只有当表面与体积之比很大以实现短寿命等离子体衍生中间体的高通量时，才能实现等离子体和表面催化化学之间的有效耦合因此，限制，实现非常高的表面与体积比，是将体积和快速等离子体化学与选择性、较慢的表面催化过程结合起来的关键。和多尺度建模，以检查影响受限反应环境中等离子体催化化学耦合的反应和传输现象，这包括（1）探测等离子体和热催化过程联合操作中反应物种的特征扩散时间尺度和寿命。在毛细管微反应器中，（2）开发光谱和光谱测量工具来识别和枚举气相和催化剂表面上的短寿命反应中间体，以及（3）开发描述这些有限反应环境中的基础过程的多尺度模型。阐明反应和传输现象如何影响等离子体催化耦合，并描述新的催化物种和氮氧化物还原途径。该项目通过“密闭空间中的化学和传输”授予。 (NSF-DFG Confine)”机会，这是一项涉及美国国家科学基金会和德国研究协会 (DFG) 的合作征集活动。该奖项是 NSF 的法定使命，通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。