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The geometrical structures, stability and electronic properties of PtmIrn and PtmIrnNO (m + n = 8 − 1 0) clusters have been studied by using density functional theory (DFT). Simple cube evolution pattern is revealed for Ir 8 − 1 0 and Ir-rich clusters. The curve of the second-order energy difference of PtnIr (9 − n) clusters shows the evident even–odd oscillations, indicating that PtIr8, Pt3Ir6, Pt5Ir4 and Pt7Ir2 clusters are more stable than their neighbors. The minimum excess energies values are seen for Pt7Ir, PtIr8 and Pt2Ir8, which means that these clusters show the stronger mixing tendency. Analysis of magnetic properties shows that the total magnetic moment contributed from Ir and Pt atoms, and the magnetic moment mainly comes from localization of the d orbit electron. All ground-state structures show an adsorption of NO at the top site of the bare cluster via the N atom. In all of the alloy clusters, NO molecule prefers to be adsorbed near the Ir atom site. Fukui function is an accurate predictor of the reactivity on a specific adsorption site in Pt–Ir alloy clusters. [ABSTRACT FROM AUTHOR]

A theoretical study was carried out of NO and H 2 O co-adsorption on Cu m Co n (2≤ m + n ≤7) clusters using density functional method. It can be found that doping H 2 O can generally promote activity of NO molecules except Co 2 NO H 2 O and Cu 2 Co H 2 O clusters. Co 4 NO H 2 O, CuCo 4 NO H 2 O and Cu 2 Co 3 NO clusters are much more stable than their neighbors, while CuCoNO H 2 O,Cu 2 CoNO H 2 O,Cu 2 Co 2 NO H 2 O,Cu 4 CoNO H 2 O,Cu 3 Co 3 NO H 2 O,Cu 6 CoNO H 2 O clusters display stronger chemical stability. Magnetic and electronic properties are also discussed. It turns out that the change of magnetic moment after H 2 O adsorption is affected not only by negative magnetic moments provided by NO and H 2 O, but also by the degree of spin polarization of Co atoms. [ABSTRACT FROM AUTHOR]