Theoretical study of CO adsorption and oxidation on the gold–palladium bimetal clusters

Density functional theory (DFT) calculations are performed to investigate CO and O2 adsorption as well as CO oxidation on the AumPdn (m + n = 2–6) bimetallic clusters. It is found that the adsorption energies of both CO and O2 on AumPdn (m + n = 2–6) are greater than those on the pure gold clusters of corresponding sizes, and unexpectedly greater than those on Pd clusters in some cases. At the same time, the calculated reaction barrier of CO oxidation on Au2Pd is lower than those on Au3 and Pd3, indicating that Au/Pd bimetallic cluster could potentially have a better catalytic activity for CO oxidation potentially.