Towards Atomically Precise Supported Catalysts from Monolayer-Protected Clusters: The Critical Role of the Support

Controlling the size and uniformity of metal clusters with atomic precision is essential for fine-tuning their catalytic properties, however for clusters deposited on supports, such control is challenging. Here, by combining X-ray absorption spectroscopy and density functional theory calculations, it is shown that supports play a crucial role in the evolution of monolayer-protected clusters into catalysts. Based on the acidic nature of the support, cluster-support interactions lead either to fragmentation of the cluster into isolated Au-ligand species or ligand-free metallic Au-0 clusters. On Lewis acidic supports that bind metals strongly, the latter transformation occurs while preserving the original size of the metal cluster, as demonstrated for various Au-n sizes. These findings underline the role of the support in the design of supported catalysts and represent an important step toward the synthesis of atomically precise supported nanomaterials with tailored physico-chemical properties.