The catalyst, usually a precious metal such as platinum, palladium, or rhodium, is used with a catalyst support material and a wash coat to disperse the catalytic materials over a wide surface area. Dr Yoshihide Watanabe, chief researcher, at the Toyota R&D Labs reviewed research on different types of catalytic reactions where metal clusters' sizes were atomically controlled.
A cluster is a group of atoms or molecules formed by interactions varying from weak to strong. Studying metal clusters offers the potential to use synthetic clusters in industrial applications, such as catalysts in catalytic converters.
Dr Watanabe points out that there has not been much research in atomically controlled cluster catalysis, apart from studies on carbon monoxide oxidation reaction. His research indicates that catalytic activity is strongly affected by the electronic structure of clusters, geometry on a support material, and the interaction between the cluster and the material. The catalytic activity of clusters can be enhanced by controlling cluster size and the interaction between the clusters and the support material. Enhancing the catalytic activity of some clusters may greatly reduce the use of precious metals as catalytic agents. Studies try to understand how the catalytic properties of size-controlled clusters are affected at the quantum level.
Watanabe recommends further studies to investigate how catalytic reaction rates are affected by temperature. He says that applying computer simulations (computational chemistry) could progress the development of quantum-controlled catalysts formed from atomically precise clusters.