Size-dependent Catalytic Activity and Geometries of Size-Selected Pt Clusters on TiO2(110) Surfaces

Scanning tunneling microscope observations show a geometrical transition from a planar structure to a 3D structure at n = 8. This geometrical transition resulted in a significant decrease in the activation energy of the CO oxidation reaction. The upper-layer Pt atoms of the 3D cluster structure that starts to form at n = 8 are low-coordinated Pt atoms, and they may play an important role in the CO oxidation reaction.