Finding the Most Catalytically Active Platinum Clusters With Low Atomicity

On a subnanometer scale, an only one-atom difference in a metal cluster may cause significant transitions in the catalytic activity due to the electronic and geometric configurations. We now report the atomicity-specific catalytic activity of platinum clusters with significantly small atomicity, especially below 20. The atomic coordination structure is completely different from that of the larger face-centered cubic (fcc) nanocrystals. Here, an electrochemical study on such small clusters, in which the atomicity ranged between 12 and 20, revealed Pt-19 as the most catalytically active species. In combination with a theoretical study, a common structure that leads to a high catalytic performance is proposed.