Enhanced catalytic activity for CO oxidation by the metal-oxide perimeter of TiO2/nanostructured Au inverse catalysts

摘要

We report the effect of metal-oxide interfaces on CO oxidation catalytic activity with inverse TiO2-nano-structured Au catalysts. The inverse nanocatalysts were prepared by depositing TiO2 via the liquid-phase immersion method on electrochemically synthesized Au nanostructure supports. The catalytic performance for CO oxidation was investigated using various amounts of Ti (i.e. 0.1-1.0 wt) on two different morphologies of Au nanostructures (i.e. nanoporous and nanorod). In comparing the different Au morphologies, we found an overall higher TOF and lower activation energy for the TiO2/nanoporous Au than those for the TiO2/nanorod Au. In addition, the CO oxidation activity increased as the Ti content increased up to 0.5 wt probably due to active TiO2-Au interface sites enhancing CO oxidation via the supply of adsorption sites or charge transfer from TiO2 to Au. However, a higher titania content (i.e. 1.0 wt TiO2) resulted in decreased activity caused by high surface coverage of TiO2 decreasing the number of TiO2 Au interface sites. These results implied that the perimeter area of the metal-oxide interface played a significant role in determining the catalytic performance for CO oxidation.