Evolution from superatomic Au(24)Ag(20) monomers into molecular-like Au(43)Ag(38) dimeric nanoclusters

Hierarchical assembly of nanoparticles has been attracting wide interest, as advanced functionalities can be achieved. However, the ability to manipulate structural evolution of artificial nanoparticles into assemblies with atomic precision has been largely unsuccessful. Here we report the evolution from monomeric Au(24)Au(20) into dimeric Au(43)Ag(38) nanoclusters: Au(43)Ag(38) inherits the kernel frameworks from parent Au(24)Ag(20) but exhibits distinct surface motifs; Au(24)Ag(20) is racemic, while Au(43)Ag(38) is mesomeric. Importantly, the evolution from monomers to dimers opens up exciting opportunities exploring currently unknown properties of monomeric and dimeric alloy nanoclusters. The Au(24)Ag(20) clusters show superatomic electronic configurations, while Au(43)Ag(38) clusters have molecular-like characteristics. Furthermore, monomeric Au(24)Ag(20) catalysts readily outperform dimeric Au(43)Ag(38) catalysts in the catalytic reduction of CO(2).