2016. 57, 1 UDC 541.272:548.737 THE CATALYTIC MECHANISM OF CO OXIDATION IN AlAu6 CLUSTERS DETERMINED BY DENSITY FUNCTIONAL THEORY A. Li, L. Guo, X. An, N. Liu, Z. Cao, W. Li, X. Zheng, Y. Shi, J. Guo, Y. Xi School of Chemistry and Material Science, School of Modern Arts and Sciences, Shanxi Normal University, Linfen 041004, China E-mail: gl-guoling@163.com Received October, 14, 2014 Revised December, 7, 2014 We present density functional calculations of O2 and CO adsorption on an AlAu6 cluster. <...> It is found that in the AlAu6 cluster the active sites would be first occupied by coming O2 rather than CO due to a more negative binding energy of the former. <...> Furthermore, the catalytic mechanisms of CO oxidation in AlAu6 clusters, which are based on a single CO molecule and double CO molecules, are discussed. <...> This investigation reveals that the reaction of a single CO molecule with the AlAu6O2 complex has the lowest activation barrier (0.27 eV), which is 0.51 eV lower than that of the pure Au 6 cluster. <...> INTRODUCTION Gold nanoparticles have attracted public attention since the pioneering discovery that Au can exhibit a surprisingly high catalytic activity [ 1 ] when it is highly dispersed on certain catalyst supports. <...> In the last years, a number of series of experimental and theoretical works have been devoted to the studies of gold-containing bimetallic clusters [ 8—15]. <...> Zhu et al. found that the catalyst performance of Au—Pd alloy nanoparticles supported by ZrO2 [ 8 ] could be enhanced by light illumination. <...> The research revealed that the equilibrium geometries of AunAl are threedimensional for n 4, which is different from pure gold clusters. <...> It is worth pointing out that the Al atom prefers to lie in the center rather than on the surface in each the ground state of AunAl (1 n 9) clusters. <...> Their calculated results also show that there is a similar odd-even alternative phenomenon for energies, second-order energy differences, highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energy <...>