The mechanism of CO oxidation catalyzed by anionic gold clusters and was investigated in detail at the B3LYP level of theory. The computational results indicated that the absorption of O2 molecules on gold clusters is easier than that of CO. The CO oxidation can take place only under the influence of cooperative effects due to the presence of more than one CO molecule. The high activation energies, which are a consequence of the partial breaking of a strong O—O bond, can be lowered by introducing the second CO molecule. The CO oxidation catalyzed by and could proceed through carbonate-like intermediates with the activation barriers of 0.607 and 0.658 eV, respectively. Both and can catalyze effectively the CO oxidation at room temperature. These results are in agreement with the previous experimental and theoretical results.

Key words: gold cluster, CO oxidation, mechanism, density functional theory