AVS 56th International Symposium & Exhibition
    Surface Science Wednesday Sessions
       Session SS2-WeM

Paper SS2-WeM10
H2O Interaction with Oxygen Adatoms on TiO2(110)

Wednesday, November 11, 2009, 11:00 am, Room N

Session: Surface Chemistry and Dynamics
Presenter: Y. Du, Pacific Northwest National Laboratory
Authors: Y. Du, Pacific Northwest National Laboratory
A. Deskins, Pacific Northwest National Laboratory
Z. Zhang, Pacific Northwest National Laboratory
Z. Dohnalek, Pacific Northwest National Laboratory
M. Dupuis, Pacific Northwest National Laboratory
I. Lyubinetsky, Pacific Northwest National Laboratory
Correspondent: Click to Email
Water and oxygen interactions on the catalytically important TiO2 surfaces have attracted great interest from both fundamental and technological points of view. In this work, surface chemistry of water on oxidized TiO2(110) surfaces is investigated by scanning tunneling microscopy studies and density functional theory calculations. We show that oxygen adatoms (Oa), generated during oxygen dissociation, alter the water dissociation and recombination chemistry through two distinctive pathways. Depending on whether H2O and Oa are on the same or adjacent Ti4+ rows, Oa facilitates H2O dissociation and proton transfer to form a terminal hydroxyl pair, positioned along or across the Ti4+ row, respectively. The latter process involves proton transfer through a bridging oxygen atom where H2O is considered to be in a ‘‘pseudo-dissociated’’ state. In both pathways, the reverse H transfer results in H2O reformation and statistical O scrambling, as manifested by an apparent along- or across-row motion of Oa’s.