Razieh Habibpour - Department of Chemical Technologies, Iranian Research Organization for Science and Technology, P.O. BOX ۳۳۵۳-۵۱۱۱, Tehran, I. R. Iran.
Raheleh Vaziri - Department of Chemistry, Payame Noor University, P.O. BOX ۱۹۳۹۵-۳۶۹۷, Tehran , I. R. Iran.

In this study, the structures, the IR spectroscopy, and the electronic properties of AunCum (n+m≤۵) bimetallic clusters were studied and compared with those of pure gold and copper clusters using the generalized gradient approximation (GGA) and exchange correlation density functional theory (DFT). The study of an O۲-AunCum system is important to identify the promotion effects of each of the two metals and their effect in catalysts, sensors, energy sources, or many other applications. This study also demonstrated that the O۲ molecule preferred to adsorb at the Cu site rather than at the Au site in bimetallic clusters. O۲ adsorption at a bridge site is energetically more favored over the other sites (۱- both oxygen atoms are bonded to the same substrate atom ۲- O۲ is connected to a Cu atom through a single bond) for oxygen adsorption on these clusters. Further, it was concluded that after the adsorption of the O۲ molecule on the bimetallic clusters, the Au-Cu interaction is strengthened and the O-O interaction is weakened; the reactivity improvement of the oxygen molecule was clear.

Bimetallic clusters, Density functional theory (DMF), Density of states, O۲ adsorption, Vibrational frequency