Gold/Titania Interfaces and Their Role in Carbon Monoxide Oxidation

The chemisorption properties of differently prepared model gold/titania interfaces have been compared with the aim of gaining a better understanding of the synergistic interplay between the constituents in gold/titania catalysts used in low-temperature CO oxidation. The structurally different gold/titania interfaces were prepared using various techniques, including wet chemical deposition (dip coating) and physical vapor deposition of TiO2 on flat and highly oriented Au(111)/mica films and immobilization of gold colloids on TiO2/Au(111)/mica films as well as on TiO2 powders. The low-temperature activity of small gold colloids anchored on films was corroborated by DRIFTS measurements. CO, CO2, and O2 adsorption/desorption studies were performed on the flat model catalysts with TDS, XPS, and ISS. All flat model systems did not show any significant CO adsorption. Oxygen desorption was evidenced by TDS. The adsorptive properties of powder model catalysts were investigated with DRIFTS, pulse thermal analysis, ...