AVS 51st International Symposium
    Surface Science Tuesday Sessions
       Session SS-TuP

Paper SS-TuP47
XPS and XAS Study of Water and Atomic Oxygen Co-absorbed on Pt(111)

Tuesday, November 16, 2004, 4:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: L.-A. Naslund, Stockholm University, Sweden
Authors: L.-A. Naslund, Stockholm University, Sweden
K. Andersson, Stockholm University, Sweden
T. Schiros, Stockholm University, Sweden
H. Ogasawara, Stanford Synchrotron Radiation Laboratory
A. Nilsson, Stanford Synchrotron Radiation Laboratory
Correspondent: Click to Email
The chemical interaction between water and a metal surface is important in many practical fields, including corrosion, electrochemistry, molecular environmental science and heterogeneous catalysis. On hexagonal metal surfaces, like Pt(111), water molecules adsorb intact with strong intermolecular forces between the water molecules. A combined X-ray photoemission spectroscopy (XPS) and x-ray absorption spectroscopy (XAS) study shows that water (D@sub 2@O) co-adsorbed with atomic oxygen on Pt(111) stimulate dissociation of the water molecule and form a saturated hydrogen bonded network of OD and D@sub 2@O in the surface plane. The interaction with the Pt(111) surface is strong and give rise to a chemical shift of the Pt 4f orbital that is different from the results for water on Pt(111). XAS with polarized light shows that OD is standing up while D@sub 2@O is laying down. The amount of OD and D@sub 2@O are 0.28 ML and 0.55 ML, respectively, which gives an OD/D@sub 2@O ratio of 2. Upon heating D@sub 2@O desorbs and a reversible process gives back atomic oxygen.