CAREER: Developing Multi-Scale Models for the Effective Design of Hydrothermally Stable Single-Site Catalysts for Low-Temperature CO Emissions Removal

该项目研究了“单位点”催化在低温汽车尾气催化中的潜在适用性，从而为高效稳定的汽车催化剂铺平了道路，该催化剂主要由地球上丰富的过渡金属组成，并辅之以低浓度的原子分散贵金属（如铂）。该研究还将产生改进的计算方法，用于基于负载催化剂的广泛化学过程的单位点催化机会和局限性的一般预测。这项研究将与塔夫茨大学的实验表面科学和催化研究以及相关的教育和推广项目相结合，目标是在高中到研究生阶段的代表性不足的群体（包括美国印第安人）。将建立一个多尺度模型来预测低温废气催化剂在实际条件下的催化行为。核心假设是，用原子分散的贵金属对第一排过渡金属氧化物进行化学改性，将显示出比纯贵金属催化剂更高的理论效率，而这些高效率将与载体控制原子分散金属氧化状态的能力有关。为此，一个综合模型-从其他小组获得的高质量特征数据开发-将用于预测废气相关反应，如CO氧化和水煤气转移反应，在原子分散的铂上，具有明确定义的铜表面氧化物支撑。教育和推广目标将展示如何将计算建模工具与实验数据结合使用，以加速发现新的催化剂材料和结构。该项目将用一种讲故事的方式向高中生解释汽车尾气催化作用，让他们对STEM学科的高等教育机会感到兴奋。

The project investigates the potential applicability of the emerging area of "single-site" catalysis to low-temperature automotive exhaust catalysis, thereby paving a path toward efficient and stable automotive catalysts comprised primarily of earth-abundant transition metals aided by low concentrations of atomically-dispersed noble metals such as platinum. The study will also yield improved computational methods for general predictions of single-site catalysis opportunities and limitations for a broad range of chemical processes based on supported catalysts. The research will be integrated both with experimental surface science and catalysis studies at Tufts and related educational and outreach programs targeting underrepresented groups (including American Indians) at the high school through graduate school levels.A multi-scale model will be developed to predict the catalytic behavior of low-temperature exhaust catalysts in real-world conditions. The central hypothesis is that the chemical modification of a first-row transition metal oxide with an atomically dispersed precious metal will display theoretical efficiencies that are superior to pure-precious-metal catalysts, and that these high efficiencies will be connected to the support's ability to control the oxidation state of the atomically dispersed metal. To this end, a comprehensive model - developed from high quality characterization data obtained from other groups - will be used to predict exhaust-gas related reactions such as CO oxidation and the water-gas shift reaction, on atomically dispersed platinum with a well-defined copper surface oxide support. The educational and outreach objectives will demonstrate how computational modeling tools can be used in conjunction with experimental data to accelerate the discovery of new catalyst materials and structures. The PI will use a story-telling approach to explain automotive exhaust catalysis to high-school students in a way that excites them about higher education opportunities in STEM disciplines.