Adsorption of gold clusters on metal-supported MgO: Correlation to electron affinity of gold

摘要: Adsorption of ${\mathrm{Au}}_{N}$ clusters $(N=1\char21{}6)$ on a bulk MgO(001) surface and an ultrathin (3 ML) film supported by Mo metal is investigated via density-functional theory calculations. Comparison the two substrates unambiguously shows that gold adsorbed $\mathrm{Mg}\mathrm{O}∕\mathrm{Mo}$ turn into singly charged cluster anions ${\mathrm{Au}}_{N}^{\ensuremath{\delta}}$, $\ensuremath{\delta}\ensuremath{\approx}\ensuremath{-}1$. Their structures internal charging patterns are analogous to charged, planar, gas-phase ${\mathrm{Au}}_{N}^{\ensuremath{-}}$. The adsorption energy has prominent size-dependent odd-even oscillations, correlating fully with known electron affinity Au in this size range.