Structural, electronic and catalytic properties of single magnesium atom doped small neutral Rhn (n=2-8) clusters: Density functional study

Rhodium nano clusters exhibit unique electronic, magnetic and catalytic properties. Physical and chemical properties of rhodium cluster can be tuned by incorporating different metal and non metal atoms. In this study magnesium doped rhodium clusters are investigated to evaluate their structure, stability, electronic and magnetic properties using density functional theory (DFT). Stability function, fragmentation energy and LUMO-HOMO gap reveals that Rh5Mg, Rh6Mg and Rh8Mg clusters are more stable than the other magnesium doped rhodium clusters. Chemical reactivity of rhodium cluster increases on doping with magnesium atom. Deformation density, density of electronic state, force vector analysis suggest that electronic redistribution are occurred to attain the higher stability in Rh5Mg as well as in Rh8Mg. Negative electrostatic potential is generally generated on rhodium atoms opposite to magnesium atom while, electrons are transferred from magnesium to rhodium atoms in magnesium doped rhodium clusters. Calculated structural, electronic and orbital parameters suggest higher stability of Rh5Mg, Rh6Mg and Rh8Mg clusters. Magnesium doped rhodium clusters are found to be more reactive than pure rhodium clusters on the basis of evaluated Fukui function values. Rh5Mg cluster is seen to be better catalyst for the dissociation of CH3OH in comparison to pure Rh-5. Activation of O-H bond is observed to be more favourable in comparison to methyl C-H bond in the dissociation of CH3OH. (C) 2017 Elsevier B.V. All rights reserved.