CAREER: Catalysis on Singly Dispersed Bimetallic Catalytic Sites

圣母大学的富兰克林(冯)陶通过化学催化项目的这一职业奖项获得资金，用于开发新型催化剂的研究。这些催化剂显示出了从废气中去除一氧化二氮等有毒气体的良好能力。通过这项研究开发的新催化剂由连接到氧化物载体上的金属原子组成。这项工作的一个独特之处是金属团簇的小尺寸。在一个由一个Rh原子与两个氧化钴分子键合的体系中，得到了良好的结果。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。研究人员正在扩大早期对Rh原子的研究，将其他贵金属包括在内，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可用于产生新的化学燃料或从环境中去除气体污染物的新的高效催化剂。该项目对下一代科学家的教育和培训产生了进一步的影响，其中包括还在上高中的年轻科学家，他们正在参加研究小组的外联工作。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置。在这项研究中，双金属催化剂颗粒正在被研究。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双金属位置组成。在所研究的单分散双金属中心的体系中，催化中心是孤立的而不是连续的，因此表现出不同的电子态和分子吸附。已经发现，反应物分子或中间体在孤立的双金属中心上的特定结合构型可以提高特定产物的催化选择性。目前的项目重点是开发3D-4D和3D-5D金属的单分散双金属位置的催化剂。用RhCo2簇已经发现了很好的结果。除Rh外，还在用Pd和Pt与钴和氧化锌载体相结合进行其他研究。

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.