GOALI: Search for a Practical Perovskite-Based Three-Way Catalyst

目标：寻找实用的钙钛矿基三效催化剂

• 批准号: 1159240
• 负责人: Xiaoqing Pan
• 金额: $ 32万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-15 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1159240&HistoricalAwards=false
• 关键词: GOALI; Search; Practical; Perovskite; Based

Abstract#1159240Pan, XiaoqingGradual coarsening of the catalytically-active metal particles in a catalyst is one of the fundamental reasons for loss of activity over time. For three-way automotive exhaust-gas catalysts, a recent phenomenon, the redox-induced cyclical re-dispersion of the metal in novel precious-metal-doped-perovskite formulations has been proposed as a possible means of reducing this problem. Recent work showing that this phenomenon occurs over distances of only a few nanometers in these systems suggests that a practical perovskite-based catalyst will likely involve ultra-thin perovskite films or coatings. In an effort to assess the viability of such a catalyst, this GOALI award covers a carefully designed combination of electron microscopy and catalytic measurements on model planar and high-surface-area powder catalysts to be conducted at University of Michigan and Ford Research and Innovation Center under the supervision of Profs. Xiaoqing Pan and George Graham and of Dr. Robert McCabe, respectively. Specific objectives include the observation of self-stabilizing or self-regenerative catalyst behavior in ultra-thin perovskite films on planar supports, the production of perovskite-coated high-surface-area powders, the measurement of kinetics and detailed chemical potential dependence of structural transformations in model powder catalyst systems, the catalytic characterization of perovskite-based precious-metal catalysts using simple reactions to probe three-way catalytic activity, and ultimately the durability assessment of perovskite-based precious-metal powder catalysts under realistic conditions. An important aspect of the structure-property relationship testing will be to clearly assign catalytic activity to either supported metal particles or metal-doped perovskite.Broader Significance and Importance: Automotive exhaust-gas catalysts currently account for 30-50% of the world-wide demand for Pt and Pd, and the corresponding demand for Rh is even higher, ~80%. Since the utilization of these metals in this application has historically never exceeded a few percent by end of life, due primarily to particle coarsening, the attainment of even a modest increase in efficiency would be of tremendous significance, both commercially as well as scientifically. The proposed work affords the opportunity for graduate and undergraduate students at University of Michigan to collaborate closely with catalyst researchers at Ford Motor Company and their suppliers in the pursuit of this goal, which is to improve metal utilization efficiency through the development of a practical perovskite-based three-way catalyst.

摘要#1159240潘晓庆催化剂中催化活性金属颗粒的逐渐粗化是随着时间的推移而失去活性的根本原因之一。对于三效汽车尾气催化剂来说，最近出现的一种现象是，氧化还原诱导的金属在新型贵金属掺杂钙钛矿配方中的循环再分散已被提议作为减少该问题的可能方法。最近的研究表明，这种现象在这些系统中仅几纳米的距离内发生，这表明实用的钙钛矿基催化剂可能涉及超薄钙钛矿薄膜或涂层。为了评估这种催化剂的可行性，该 GOALI 奖涵盖了电子显微镜和催化测量的精心设计组合，将在密歇根大学和福特研究与创新中心对模型平面和高表面积粉末催化剂进行催化测量在教授的监督下。分别是潘晓庆和乔治·格雷厄姆以及罗伯特·麦凯布博士。具体目标包括观察平面载体上超薄钙钛矿薄膜的自稳定或自再生催化剂行为、钙钛矿涂层高表面积粉末的生产、动力学测量和结构转变的详细化学势依赖性在模型粉末催化剂系统中，使用简单的反应对钙钛矿基贵金属催化剂进行催化表征，以探测三效催化活性，并最终评估钙钛矿基贵金属粉末的耐久性现实条件下的催化剂。 结构-性能关系测试的一个重要方面是明确将催化活性分配给负载金属颗粒或金属掺杂钙钛矿。 更广泛的意义和重要性：汽车尾气催化剂目前占全球的 30-50% Pt 和 Pd 的需求量，Rh 的相应需求量更高，约 80%。由于这些金属在该应用中的利用率在历史上从未超过寿命结束时的百分之几，这主要是由于颗粒粗化，因此即使效率的适度提高也将具有巨大的商业和科学意义。拟议的工作为密歇根大学的研究生和本科生提供了与福特汽车公司及其供应商的催化剂研究人员密切合作以实现这一目标的机会，即通过开发实用的钙钛矿-基三元催化剂。