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

Paper SS-TuP49
Water Dissociation on Ru(001): An Activated Process

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

Session: Poster Session
Presenter: H. Ogasawara, Stanford Synchrotron Radiation Laboratory
Authors: H. Ogasawara, Stanford Synchrotron Radiation Laboratory
K. Andersson, Stanford Synchrotron Radiation Laboratory, Stockholm University, Sweden
T. Schiros, Stockholm University, Sweden
A. Nikitin, Stanford University
L.G.M. Pettersson, Stockholm University, Sweden
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 Pt(111), it was shown that in the first layer all the molecules bind directly to the surface and to each other through the in-layer H-bonds without dissociation, creating a nearly flat overlayer. The water molecules are adsorbed through alternating metal-oxygen (M-O) and metal-hydrogen (M-HO) bonds@footnote 1@. On Ru(001), the water layer on Ru(001) shares similarities with the first water layer on Pt(111). We, however, obtained a dissociated state by irradiation of the adsorbed film by x-rays or heating the surface in water vapor above the desorption temperature. The latter shows a clear isotope effect between H20 and D2O indicating an activated dissociation process with a barrier slightly larger than the desorption channel. Previous theoretical and experimental disagreements can be explained in terms of electron or x-ray beam induced dissociation and under estimation of the dissociation barrier. We will also discuss about the bonding mechanism of water on Ru(001) based on DFT calculation. @FootnoteText@ @footnote 1@ H. Ogasawara et al, Phys. Rev. Lett. 89 (2002). .