Preparation and reactivity of Rh nanoparticles on TiO2(110)-(1×2) surface

Arrays of Rh nanoparticles with independently controlled sizes and average distances were prepared by exploiting the surface temperature-dependent kinetics of the Rh adatoms and nanocluster migration processes on TiO2(110)-(1×2) surface. The supported Rh nanoparticles fabricated in this way exhibit a very narrow size distribution. The characteristic particle diameter can be varied in the range of 2–20 nm with a desired interparticle distance tunable between 5 and 100 nm. The distribution and the morphology of the nanoparticles were characterized by scanning tunneling microscopy. The advantage of this method in comparison with lithography techniques is its relative simplicity and the possibility of the preparation of metal particles in the typical ‘catalytic regime’. The model catalysts so produced are applicable in the study of size-dependent reactivity of the nanoparticles (gas-induced disruption, agglomeration, encapsulation, catalytic activity). It is also suggested that the tailored particle arrays can serve as templates for further nanostructural fabrication.