Catalytic Role of Metal Oxides in Gold-based Catalysts: A First Principles Study of CO Oxidation on TiO2 Supported Au

Z. P. LIU; X. GONG; J. J. KOHANOFF; C. G. SANCHEZ; P. HU

PHYSICAL REVIEW LETTERS

Año: 2003 vol. 91 p. 266102 - 266106

0031-9007

CO oxidation on TiO2 supported Au has been studied using density functional theory calculations.Important catalytic roles of the oxide have been identified: (i) CO oxidation occurs at the interfacebetween Au and the oxide with a very small barrier; and (ii) O2 adsorption at the interface is the key step in the reaction. The physical origin of the oxide promotion effect has been further investigated: The oxide enhances electron transfer from the Au to the antibonding states of O2, giving rise to (i) strong ionic bonding between the adsorbed O2, Au, and the Ti cation; and (ii) a significant activation of O2 towards CO oxidation.