NSF/DOE Advanced Combustion Engines: Collaborative Research: GOALI: Understanding NOx SCR Mechanism and Activity on Cu/Chabazite Structures throughout the Catalyst Life Cycle

NSF/DOE 先进内燃机：合作研究：GOALI：了解 NOx SCR 机制以及整个催化剂生命周期中铜/菱沸石结构的活性

• 批准号: 1258715
• 负责人: Fabio Ribeiro
• 金额: $ 84.38万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-15 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1258715&HistoricalAwards=false
• 关键词: NSF; DOE; Advanced; Combustion; Engines

ABSTRACT#1258715 - Fabio Ribeiro#1258690 - William Schneider#1258717 - Jean-Sabin McEwenThe lack of a practical and cost-effective lean NOx aftertreatment is the major obstacle to the widespread adoption of fuel-efficient diesel and lean-burn gasoline engines for transportation. Increasingly stringent NOx emissions standards demand that NOx conversion to N2 reach or exceed 90% averaged over standard drive cycles, and even higher instantaneous conversions to compensate for cold startup and transient operation. These high conversions are very difficult to achieve under lean conditions, in which NOx must compete with an overwhelming excess of O2 for a limited amount of reductant. Lean NOx traps can achieve the necessary NOx conversion efficiencies, but have many operational and cost issues in their current forms. NOx selective catalytic reduction (SCR) provides a much more satisfactory solution to lean NOx aftertreatment. In this approach the usual converter catalyst is replaced with a catalyst that promotes reaction of NOx with a reductant, such as urea, NH3, or hydrocarbons, to produce N2 selectively over the competing reactions of reductant with O2.The selective catalytic reduction with ammonia on Cu-exchanged chabazite zeolites is the state-of-the-art for lean NOx reduction and enables access to the fuel efficiency of lean burn engines. Although these materials are used commercially in a small segment of the transportation market, their structure and catalytic behavior changes in unpredictable ways as they respond to varying SCR conditions and in particular as they accumulate deactivating sulfur species. Real-world application of these catalysts at Cummins reveals that their performance at low temperatures is diminished in ways not explained by previously published aging mechanisms. The primary obstacle to the rational improvement and effective application of NOx SCR catalysts is the lack of a firm fundamental understanding of the underlying catalyst structure and catalytic chemistry.An approach to filling this knowledge gap to lead to maximum SCR catalyst performance has been proposed in response to the joint National Science Foundation and Department of Energy solicitation on Advanced Combustion Engines. The joint Agency award is made through the NSF Chemical, Bioengineering, Environmental and Transport Systems Division and its Catalysis & Biocatalysis Program to a multi-disciplined team made up of Professors Fabio H. Ribeiro, W. Nicholas Delgass, and Rajamani Gounder at Purdue University; Prof. Jean-Sabin McEwen at Washington State University; and Prof. William F. Schneider at University of Notre Dame; Dr. Jeffrey T. Miller, Argonne National Laboratory; Dr. Charles H. F. Peden, Pacific Northwest National Laboratory; and Dr. Aleksey Yezerets, Cummins Inc.NSF GOALI support is also provided to this team that has many years of combined industrial, National Laboratory and academic experience in NOx catalysis and catalysis science and a proven record of successful collaboration.To dramatically improve the present catalyst materials, to optimize engine efficiency within emission constraints, and to circumvent deactivation, an atomic and molecularly detailed model of catalyst performance under all operating conditions and throughout the life cycle is essential. This team brings world-class excellence in the variety of experimental and theoretical disciplines that must be combined to reach the atomic-level understanding of the dynamic chemical and catalytic properties of this reaction system, which will form the basis of a predictive model for this SCR catalyst system and for further catalyst system improvements. Though the students working on this project will specialize in particular aspects of the research, frequent teleconferences with the entire team and groups traveling to the National Labs to do specialized experiments will provide broad experience and direct exposure to the importance of the interplay between various experiments and molecular theory at the frontier of catalysis research. Thus, this multi-institutional and diverse team will prepare graduate students and postdocs to operate at the highest levels in application of catalysis to the solution of energy efficiency and environmental problems. It will also provide career-defining educational opportunities to high school and undergraduate students. For high school students and educators, Purdue has already developed a hands-on presentation to interest students in science and engineering. The PIs intend to add the molecular view of this work to that presentation and deliver lectures to high schools across Indiana and to bring this view to the many science and engineering camps that run at Purdue and Notre Dame during the summer. Undergraduates working in the university research groups and in industrial internships at Cummins will also benefit from the breadth of scientific exposure and the unique approach that connects detailed fundamental understanding to the solution of important practical problems.

摘要#1258715 - Fabio Ribeiro#1258690 - William Schneider#1258717 - Jean-Sabin McEwen缺乏实用且具有成本效益的稀薄氮氧化物后处理是广泛采用节能柴油和稀燃汽油发动机用于运输的主要障碍。日益严格的 NOx 排放标准要求 NOx 转化为 N2 的平均转化率达到或超过标准驾驶周期的 90%，甚至要求更高的瞬时转化率，以补偿冷启动和瞬态运行。这些高转化率在贫油条件下很难实现，在贫油条件下，NOx 必须与大量过量的 O2 竞争有限数量的还原剂。稀氮氧化物捕集器可以实现必要的氮氧化物转化效率，但其当前形式存在许多操作和成本问题。 氮氧化物选择性催化还原 (SCR) 为稀氮氧化物后处理提供了更令人满意的解决方案。在这种方法中，通常的转化器催化剂被替换为促进NOx与还原剂（例如尿素、NH3或碳氢化合物）反应的催化剂，以在还原剂与O2的竞争反应中选择性地产生N2。氨的选择性催化还原铜交换菱沸石是最先进的稀薄氮氧化物还原技术，可实现稀薄燃烧发动机的燃油效率。尽管这些材料在运输市场的一小部分中得到商业使用，但当它们响应不同的 SCR 条件时，特别是当它们积累失活的硫物质时，它们的结构和催化行为会以不可预测的方式发生变化。这些催化剂在康明斯的实际应用表明，它们在低温下的性能会以先前公布的老化机制无法解释的方式下降。 NOx SCR 催化剂合理改进和有效应用的主要障碍是对催化剂结构和催化化学缺乏牢固的基本了解。为此，提出了一种填补这一知识空白以实现最大 SCR 催化剂性能的方法。国家科学基金会和能源部联合征集先进内燃机。该联合机构奖是通过 NSF 化学、生物工程、环境和运输系统部门及其催化和生物催化计划颁发给由普渡大学 Fabio H. Ribeiro、W. Nicholas Delgass 和 Rajamani Gounder 教授组成的多学科团队;华盛顿州立大学 Jean-Sabin McEwen 教授；以及圣母大学的 William F. Schneider 教授； Jeffrey T. Miller 博士，阿贡国家实验室； Charles H. F. Peden 博士，太平洋西北国家实验室； NSF GOALI 还向该团队提供支持，该团队在氮氧化物催化和催化科学方面拥有多年的工业、国家实验室和学术综合经验，并拥有成功合作的良好记录。催化剂材料，为了在排放限制内优化发动机效率，并避免失活，在所有操作条件和整个生命周期下催化剂性能的原子和分子详细模型至关重要。该团队在各种实验和理论学科方面取得了世界级的卓越成就，必须将这些学科结合起来才能达到对该反应系统的动态化学和催化特性的原子级理解，这将构成该 SCR 预测模型的基础催化剂系统并进一步改进催化剂系统。尽管从事该项目的学生将专注于研究的特定方面，但与前往国家实验室进行专门实验的整个团队和小组进行频繁的电话会议将提供广泛的经验并直接了解各种实验和研究之间相互作用的重要性。催化研究前沿的分子理论。因此，这个多机构和多元化的团队将为研究生和博士后做好准备，使其在催化应用解决能源效率和环境问题方面处于最高水平。它还将为高中生和本科生提供职业定义的教育机会。 对于高中生和教育工作者，普渡大学已经开发了一个实践演示，以激发学生对科学和工程的兴趣。 PI 打算将这项工作的分子观点添加到演示文稿中，并向印第安纳州各地的高中进行讲座，并将这种观点带到普渡大学和圣母大学夏季举办的许多科学和工程营。 在康明斯大学研究小组和工业实习中工作的本科生也将受益于广泛的科学接触和将详细的基础理解与重要实际问题的解决方案联系起来的独特方法。