Abstrakt

Effect of surface site on the Spin state for the interaction of NO with Pd2, Rh2 and PdRh nanoparticles supported at regular and defective MgO (001) surfaces

S.Abdel Aal

An attempt has been made to analyze the effect of surface site on the spin state for the interaction of NO with Pd2, Rh2 and PdRh nanoparticles that supported at regular and defectiveMgO (001) surfaces. The adsorption properties of NO on homonuclear, Pd2, Rh2, and heteronuclear transitionmetal dimers, PdRh, that deposited onMgO (001) surface have been studied bymeans of hybrid density functional theory calculations and embedded cluster model. The most stable NO chemisorption geometry is in a bridge position on Pd2 and a top configuration of Rh2 and PdRhwithN-down oriented. NO prefers binding to Rh site when both Rh and Pd atoms co-exist in the PdRh. The natural bond orbital analysis (NBO) reveals that the electronic structure of the adsorbedmetal represents a qualita-tive change with respect to that of the free metal. The adsorption properties ofNOhave been analyzed with reference to the NBO, charge transfer, band gaps, pairwise and non-pairwise additivity. The binding of NO precursor is dominated by the Mx NO E(i)  pairwise additive components and the role of the support was not restricted to supporting the metal. The adsorbed dimers on theMgOsurface lose most of the metal–metal interaction due to the relatively strong bond with the substrate.