AVS 50th International Symposium
    Surface Science Monday Sessions
       Session SS3-MoA

Paper SS3-MoA5
Dynamics and Chemical Reactivity of Au on TiO@sub2@ (110) Rutile

Monday, November 3, 2003, 3:20 pm, Room 328

Session: Structure and Reactivity of Metal Clusters
Presenter: D. Pillay, University of Texas at Austin
Authors: D. Pillay, University of Texas at Austin
Y. Wang, University of Texas at Austin
G.S. Hwang, University of Texas at Austin
Correspondent: Click to Email
Au has long been known to be chemically inert in its bulk form, as compared to other transition metals, such that it has received little attention as a catalyst. However, Au nanoclusters dispersed on oxide (particularly TiO@sub2@) shows an extraordinarily high activity for low-temperature catalytic combustion, partial oxidation of hydrocarbons, hydrogenation of unsaturated hydrocarbons, and reduction of nitrogen oxides. But, due to weak metal-oxide interfacial bonding interactions, Au nanoclusters become unstable toward sintering even at moderate temperatures. This may in turn undermine their catalytic activity and selectivity. Hence, along with their chemical reactivity, a detailed understanding of dynamical behaviors of Au atoms is necessary for an accurate description of underlying reaction mechanisms and performance of the oxide supported nanometal catalytic systems under realistic processing conditions. In this talk, we will present our first principles [DFT with plane waves and pseudopotentials] study of Au adsorption and diffusion on regular and defective (with oxygen vacancies) TiO@sub2@ (110) rutile. We will also present the diffusion of oxygen vacancies (Fs center) and their interactions with Au atoms. Based on our calculation results, we will discuss underlying reasons for the enhancement of Au cluster sintering upon exposure to a high-pressure oxygen environment.