Controlled Synthesis of Rh Nanoparticles on TiO2(110) via Rh(CO)2(acac)

Abstract

The adsorption of Rh(CO)2(acac) (acac is acetylacetonate) on a TiO2(110) single crystal surface has been examined using a combination of scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. When Rh(CO)2(acac) is deposited onto the TiO2(110) surface at room temperature, features are observed by STM suggesting monomeric species that bind preferentially to oxygen vacancy sites. DFT calculations suggest that these features must be partially deligated organometallic species and that oxygen vacancies are critical to the deligation process. Exposing the observed surface species to CO at 373 K results in the formation of clusters approximately 2–3 nm in diameter and 0.3–0.8 nm in height.