|Michael Sullivan Online|
Study of Pd-Au bimetallic catalysts for CO oxidation reaction by DFT calculations
Jia Zhang, Hongmei Jin, Michael B. Sullivan, Freda Chiang Huay Lim, and Ping Wu
Institute of High Performance Computing, 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632 Singapore
(Received 28 August 2008; accepted 27 November 2008; published 19 January 2009)
Phys. Chem. Chem. Phys., 2009, 11, 1441-1446.
First-principle calculations were carried out to examine the catalytic activity of Pd and Pd-Au alloy surface for CO oxidation. The influence of surface-ligand effect and lattice strain effect on activity was demonstrated. The catalytic efficiency of Pd-Au bimetallic systems depends largely on the surface composition of Pd and Au. The addition of Au significantly improves the activity of Pd-Au bimetallic slab with Au-rich surface due to the dominant Au-induced ligand effect on both O and CO chemisorption. Among various considered cases, the system with Au on the surface of the Pd16Au4 slab exhibits lowest energy barrier of 0.21 eV, which is decreased by 0.66 eV compared to that of the pure Pd (111) surface. It is predicted that the [Pd](Au) core/shell nanoparticle catalyst should have a higher activity for CO oxidation reaction as it combines the advantages of the ligand effect of Au and the strain effect of Pd.