Atomic-Scale Understanding of Gold Cluster Growth on Different Substrates and Adsorption-Induced Structural Change

Abstract

To fully understand the properties of functional nanocatalysts including nanoclusters and nanoparticles, it is necessary to know the geometric and electronic structures of the nanostructure. The catalytic properties of noble metal nanoclusters can often be improved by the formation of heterostructures on different support, but little is known about their atomic-scale structures and their interaction with the support materials. Here, we report the size- and support-dependent structures for Au nanoclusters by combining aberration-corrected scanning transmission electron microscopy and density functional theory calculations. We demonstrate lattice-induced epitaxial coherence growth for Au nanoclusters on crystalline substrate of (110) MgO, different from the chainlike or random structures on amorphous carbon support. The time sequential atomic scale observations confirm that Au clusters tend to easily migrate on crystalline MgO support. DFT calculations based on the experiment results imply the CO adsorption...