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

Paper SS3-MoA3
Gold Nano-Clusters on Rutile TiO@sub 2@(110) - A Combined UHV and High Pressure STM Study

Monday, November 3, 2003, 2:40 pm, Room 328

Session: Structure and Reactivity of Metal Clusters
Presenter: F. Besenbacher, Interdisciplinary Nanoscience Center, Denmark
Authors: E. Walström, Interdisciplinary Nanoscience Center, Denmark
R. Schaub, Interdisciplinary Nanoscience Center, Denmark
E.K. Vestergaard, Interdisciplinary Nanoscience Center, Denmark
A. Ronnau, Interdisciplinary Nanoscience Center, Denmark
F. Besenbacher, Interdisciplinary Nanoscience Center, Denmark
Correspondent: Click to Email
Through an interplay between scanning tunneling microscopy (STM) and density functional theory (DFT) calculations, we show that bridging oxygen vacancies are the active nucleation sites for Au clusters grown on the rutile TiO@sub 2@(110) surface under UHV conditions. We show both experimentally and theoretically that a single oxygen vacancy can bind 3 Au atoms on average. A new growth model for the Au/TiO@sub 2@(110) system involving vacancy-cluster complex diffusion is presented. The fate of the Au nano-particles in various gas environments is studied in detail through a new high-pressure STM capable of atomic resolution at atmospheric pressures. Sintering and morphological changes are followed in-situ when the Au/TiO@sub 2@(110) system is exposed to reducing (H@sub 2@,CO) and oxidizing (O@sub 2@) conditions.