Nucleation behavior of supported Rh nanoparticles fabricated from Rh(CO)2(acac) on Al2O3/Ni3Al(111)

In this combined DFT and STM study, the adsorption of rhodium dicarbonyl acetylacetonate (Rh(CO)(2)(acac)) on an Al2O3 thin film and the subsequent formation of Rh deposits have been examined. When Rh(CO)(2)(acac) is deposited on the Al2O3/Ni3Al(1 1 1) surface, the molecule is observed to bind preferentially to specific sites associated with the film superstructures. DFT calculations suggest that the parent molecule, however, must be at least partially deligated as its interaction with the substrate is very weak. In contrast, Rh clusters are adsorbed strongly to defect structures associated with the film. In addition, it has been shown that by annealing the substrate to higher temperature, the particle growth on the oxide changes from 2D islands to 3D clusters. (C) 2012 Elsevier B.V. All rights reserved.