Electronic structure of palladium and gold-palladium nano clusters, both free and supported on MgO(100)

Ideal (or model) metal nano-clusters, both free and supported on MgO(100), have been the subject of numerous experimental studies. This work probes the characteristics of non-ideal systems. For that, palladium nano clusters first were synthesized using a sol-gel-microwave method. A mono-phase of metallic Pd was obtained as corroborated by thermo gravimetric analysis, x-ray powder diffraction, scanning electron microscopy, and high resolution transmission electron microscopy studies (HRTEM). Among the HRTEM micro-graphs we found an almost planar nano-surface (facet) with only forty six atoms (Pd$_{46}$). From that micro-graph we obtained the coordinates of the atoms in the Pd$_{46}$ nano-surface. With those coordinates, we did a DFT study of the Pd$_{46}$ nano-surface electronic structure. From the Pd$_{46}$nano surface, nine and eighteen Pd atoms were chosen to build A$_8$Pd$_9$ and A$_8$Pd$_{18}$ clusters respectively. Starting from a near-planar Au8 cluster, the Au$_8$ geometry was optimized over the fixed Pd$_9$ and Pd$_{18}$ nano-surfaces, charge transfer was determined with charge density difference analysis (CDDA) and Fukui analysis was done and. The Au$_8$Pd$_9$ cluster was positioned on an MgO(100) surface with an O vacancy and charge transfer was determined with CDDA