Growth, stability, and electronic decoupling of Pt clusters on h-BN/Ir(111)

Motivated by the relevance of Pt clusters in heterogeneous catalysis, ordered Pt cluster superlattices are templated by the moiré of monolayer hexagonal boron nitride (h-BN) with Ir(111). Using X-ray photoelectron spectroscopy, scanning tunneling microscopy, and scanning tunneling spectroscopy, we provide a comprehensive picture for the mechanism of cluster binding, the thermal stability of clusters, cluster superlattice decay, the morphological evolution of cluster shape with size, and finally Pt cluster decoupling and internal electronic structure. The key findings are that the Pt cluster superlattices on h-BN on Ir(111) are thermally more stable than any other Pt cluster superlattice, are well decoupled from their substrate, and display a discrete cluster height-dependent electronic structure.