A comparative theoretical study of the catalytic activities of Au (2) (-) and AuAg- dimers for CO oxidation

作者：Liu Peng; Song Ke; Zhang Dongju^*; Liu Chengbu

来源：Journal of Molecular Modeling, 2012, 18(5): 1809-1818.

DOI：10.1007/s00894-011-1210-5

• AuAg-
• CO Oxidation
• Au-2(-)
• DFT

The detailed mechanisms of catalytic CO oxidation over Au (2) (-) and AuAg- dimers, which represent the simplest models for monometal Au and bimetallic Au-Ag nanoparticles, have been studied by performing density functional theory calculations. It is found that both Au (2) (-) and AuAg- dimers catalyze the reaction according to the similar mono-center Eley-Rideal mechanism. The catalytic reaction is of the multi-channel and multi-step characteristic, which can proceed along four possible pathways via two or three elementary steps. In AuAg-, the Au site is more active than the Ag site, and the calculated energy barrier values for the rate-determining step of the Au-site catalytic reaction are remarkably smaller than those for both the Ag-site catalytic reaction and the Au (2) (-) catalytic reaction. The better catalytic activity of bimetallic AuAg- dimer is attributed to the synergistic effect between Au and Ag atom. The present results provide valuable information for understanding the higher catalytic activity of Au-Ag nanoparticles and nanoalloys for low-temperature CO oxidation than either pure metallic catalyst.

• 出版日期2012-5
• 单位山东大学