Size and Shape Dependence of the Electronic Structure of Gold Nanoclusters on TiO₂

Understanding the mechanism behind superior catalytic power of single- or few-atom heterogeneous catalysts has become an important topic in surface chemistry. This is particularly case for gold, with TiO2 being efficient support. Here we use scanning tunneling microscopy/spectroscopy theoretical calculations to investigate adsorption geometry and local electronic structure several-atom Au clusters on rutile TiO2(110), fabricated by controlled manipulation single atoms. Our study confirms that Au1 Au2 prefer at O vacancies. Au3 adsorb vacancies a linear-chain configuration parallel surface; absence they Ti5c sites vertically pointing upright triangle. We find both cluster–substrate charge transfer depend critically cluster size, bonding configuration, environment. suggests possibility engineering selectivity specific reactions.