CAREER: Catalysis on Singly Dispersed Bimetallic Catalytic Sites

圣母大学的富兰克林（冯）陶是通过化学催化计划的研究开发新型催化剂的职业奖资助的。这些催化剂显示出有希望的能力，以消除有毒气体，如一氧化二氮的废气。通过这项研究开发的新催化剂由金属原子结合到氧化物载体上组成。这项工作的一个独特之处是金属簇的小尺寸。从由单个铑原子键合到两个钴氧化物分子的系统中已经获得了良好的结果。这些系统比工业工作中通常使用的系统小得多，这种尺寸优势可能会导致性能的改善。研究人员正在将早期对铑原子的研究扩展到其他贵金属，特别是钯和铂，希望进一步提高催化活性。该项目的更广泛影响包括开发新的高效催化剂，可用于生产新的化学燃料或从环境中去除气体污染物。该项目正在对下一代科学家的教育和培训产生进一步的影响，包括正在参加研究小组外联工作的仍在上高中的非常年轻的科学家。正在开发的催化剂是多相的，这意味着催化事件发生在由金属原子、载体或两者组成的催化位点上。在这项研究中，正在研究催化剂颗粒。这些是双原子团簇（换句话说，二聚体），通常由尺寸在纳米范围内的连续多晶点组成。在这里研究的系统中，这是单分散的催化位点，催化位点是孤立的，而不是连续的，因此表现出不同的电子状态和分子吸附。已发现反应物分子或中间体在分离的催化剂位点上的特异性结合构型增强了对特定产物的催化选择性。本项目的重点是开发3d-4d和3d-5d金属单分散金属的催化剂。已经用RhCo 2簇发现了良好的结果。除了Rh之外，还正在用Pd和Pt与钴和锌氧化物载体组合进行其他研究。

Franklin (Feng) Tao of the University of Notre Dame is funded through this CAREER award by the Chemical Catalysis program for research to develop new types of catalysts. These catalysts show promising abilities to remove poisonous gases such as nitrous oxide from exhaust. The new catalysts being developed through this research consist of metal atoms bonded to an oxide support. A unique feature of this work is the small size of the metal clusters. Good results have been obtained from a system consisting of a single rhodium atom bonded to two cobalt oxide molecules. These systems are much smaller than those typically used in industrial work and this size advantage could lead to improved properties. The investigators are extending earlier research with rhodium atoms to include other precious metals, in particular palladium and platinum, with the hopes to further improve catalytic activity. The broader impacts of this project include the development of new efficient catalysts that could be used to generate new chemical fuels or to remove gaseous contaminants from the environment. The project is having a further impact on the education and training of the next generation of scientists, including very young scientists still in high school who are participating in outreach efforts of the research team. The catalysts being developed are heterogeneous, which means that the catalytic event occurs on a catalytic site consisting of atoms of metal, support, or both. In this research, bimetallic catalyst particles are being investigated. These are two-atom clusters (dimers, in other words), which typically consist of continuous bimetallic sites that have a size in the nanometer range. In the systems studied here, which are singly dispersed bimetallic sites, the catalytic sites are isolated rather than continuous and thus exhibit a different electronic state and molecular adsorption. The specific binding configuration of a reactant molecule or intermediate on an isolated bimetallic site has been found to enhance catalytic selectivity for specific products. The current project focuses on the development of catalysts of singly dispersed bimetallic sites of 3d-4d and 3d-5d metals. Good results have already been found with RhCo2 clusters. Additional studies are being carried out with Pd and Pt, in addition to Rh, combined with both cobalt and zinc oxide supports.