In the present work, we discuss the electronic properties of supported dispersed bimetallic clusters with respect to their size, geometry, and Aun/Agm (n + m = 6) composition. We have studied with supercell-density functional theory calculations the role of the charge transfer from the MgO defective support toward the cluster in the activation of O2 by AunAgm clusters. We first considered gas-phase clusters with different atomic compositions; then, we deposited all of them on a pristine (100)MgO surface and finally on a more realistic (100)MgO F-center. We performed a global and unrestricted search of the (cluster + surface) geometry. The Mexican enhanced genetic algorithm has been used to exhaustively explore the potential energy surface. Our results show that O2 activation depends on the Aun/Agm ratio. It has been found that both metals involved play different and important roles toward (a) the actual O2 dissociation and (b) weakening of the oxygen-cluster bond, which, in turn, may promote the possibility of a catalytic process to take place, such as the oxidation process of CO and NOx among others.

中文翻译：

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AuAg激活的O2聚集在有缺陷的（100）MgO表面上。

在当前的工作中，我们讨论了支撑的分散双金属簇的电子性质，关于它们的大小，几何形状和Aun / Agm（n + m = 6）组成。我们已经用超细胞密度泛函理论研究了在AunAgm团簇激活O2时，从MgO缺陷载体向团簇转移电荷的作用。我们首先考虑了具有不同原子组成的气相团簇。然后，我们将它们全部沉积在原始的（100）MgO表面上，最后沉积在更逼真的（100）MgO F中心上。我们对（群集+曲面）几何进行了全局且不受限制的搜索。墨西哥增强遗传算法已被用来详尽地探索势能面。我们的结果表明O2活化取决于Aun / Agm比。