Measurements of d-band Center Shifts of Titanium Dioxide Catalyst Using Gold Nanoparticles in Carbon Monoxide Oxidation Reaction | ||
| Iraqi Journal of Applied Physics | ||
| Article 1, Volume 14, Issue 3, December 2018, Pages 3-11 | ||
| Authors | ||
| Abbas K. Hashem; Ahmed K. Jwad; Sami R. Hmeed; Hussain A. Fadil | ||
| Abstract | ||
| It was reported previously that O adatoms adsorbed dissociatively on the 5-fold Ti rows of rutile TiO2 made the surface O-rich and reacted with CO molecules to form CO2. An electronic charge transfer taking place from gold nano-clusters to the O-rich TiO2 support played a crucial role to enhance the catalytic activity. In this study, we have further accumulated experimental data for the CO oxidation reaction enhanced by gold nano-clusters on the TiO2 surface. Based on the results obtained here and previously, we propose an “interface dipole model”, which explains the strong activity of Au nano-clusters supported on O-rich TiO2 in CO oxidation reaction. Simultaneously, we also discuss the cationic cluster model and the d-band model. The latter is, in particular, widely accepted to explain the activities of heterogeneous catalysts. Contrary to the d-band model, our ab initio calculations demonstrate that the d-band center for Au nano-clusters moves apart from the Fermi level with decreasing the cluster size and this is due to contraction of the Au-Au bond length. | ||
| Keywords | ||
| TiO; Carbon monoxide; Oxidation reaction; Nanoclusters | ||
|
Statistics Article View: 115 PDF Download: 35 |
||