Water on rutile TiO2(110) and Au/TiO2(110):: Effects on an mobility and the isotope exchange reaction

The behavior of adsorbed water on rutile TiO2 (110) and 0.05 ML-equivalent Au/TiO2 (110) have been probed over the temperature range from 110 to 800 K using a combination of temperature-programmed desorption (TPD), ion scattering spectroscopy (ISS), and X-ray photoelectron spectroscopy (XPS). Water, either predosed in order to hydroxylate vacancy sites on the surface prior to Au deposition, or dosed after An deposition onto clean vacuum-annealed TiO2, results in more facile agglomeration of the initially dispersed Au atoms compared to An deposited on vacuum-annealed TiO2. TPD indicates that the presence of Au binding at oxygen vacancy sites blocks dissociative chemisorption of water.