AVS 52nd International Symposium
    Surface Science Monday Sessions
       Session SS-MoP

Paper SS-MoP31
Structure and Growth of Small Au Particles on TiO@sub 2@(110)

Monday, October 31, 2005, 5:00 pm, Room Exhibit Hall C&D

Session: Surface Science Poster Session
Presenter: D. Pillay, The University of Texas at Austin
Authors: D. Pillay, The University of Texas at Austin
G. Hwang, The University of Texas at Austin
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*****PLEASE NOTE: YOU MUST IDENTIFY A DIFFERENT PRESENTER FOR THIS ABSTRACT. YOU MAY PRESENT ONLY ONE (1) PAPER AT THE CONFERENCE*****While Au is known to be chemically inert in its bulk form, nanometer size Au particles dispersed on TiO@sub 2@ have been found to exhibit high activities for a variety of catalytic oxidation processes at or below room temperature. Au atoms weakly interact with the TiO@sub 2@ surface and become unstable toward sintering in response to changes in the gaseous environment even at moderate temperatures. Given the weak Au-TiO@sub 2@ interfacial interaction, Au particle nucleation is thought to predominantly occur at the sites of surface defects, such as (bridging) oxygen vacancies. Similarly, during oxidation processes, a reactant O@sub 2@ molecule may adsorb on the vacancy site molecularly or completely heal the defect (while ejecting an oxygen atom). Oxygen species may also interact with Au particles directly or indirectly. Thus, oxygen adspecies can greatly alter TiO@sub 2@ surface properties and Au-TiO@sub 2@ interfacial interactions, which may in turn influence the nucleation, growth, and sintering of Au particles. In this poster, we will present the results of our recent density functional theory calculations on the interactions between oxygen species and small Au particles on TiO@sub 2@ (110), with a focus on understanding i) the dynamics of oxygen species on Au/TiO@sub 2@ and ii) the effect of oxygen species on Au particle nucleation, growth, and sintering.