Kombination von ab initio-Berechnungen mit kinetischen Simulationen von Oberflächenreaktionen im Hinblick auf die Weiterentwicklung von Autoabgas-Katalysatoren
Zusammenfassung der Projektergebnisse
The main conclusions that can be drawn from the DFG sponsored project are the following: 1. We put an explanation for the enhancement of the activity of rhodium by incorporation of coinage metal forward and we support this proposal by detailed analysis of the density of states of the alloy structure. This analysis also provides a technique, which might aid the screening of bimetallic catalysts by means of DFT and provides a more precise alternative to the d-band centre approach. 2. A method which combines the advantages of kinetic simulations of the Arrhenius-type as well as Monte-Carlo was established and applied in investigations of surface diffusion on TiO2{110} as well as diffusion and reaction on Rh{211}. 3. Combined with the resuhs from a subsequent EPSRC sponsored project, insight into the activation at steps and on low-index surface could be gained. The activation of stable chemical bonds in diatomic molecules such as CH or CO needs steric as well as electronic activation. At steps the electronic activation is due to under-coordinated metal atoms at the ridge and the steric activation is the leaning of the bond towards the ridge (which decreases the distance between start and end point of the atom that is removed by the surface). On flat, low-index surfaces the diatomic molecule has to be either oxidised or hydrogenated, which weakens the stable carbon-oxygen or carbon-hydrogen bond (electronic effect) and this reaction also tilts this bond towards the surface, which reduces the distance between start and end point of the atom to be removed (steric effect).
Projektbezogene Publikationen (Auswahl)
- 'Adsorption, Diffusion and Desorption of Chlorine on and from Rutile TiO2 {110}: A Theoretical Investigation '. ChemPhysChem 2007, 8, 444 - 451
O.R. Inderwildi, M. Kraft
- 'An Unexpected Pathway for the Catalytic Oxidation of Methylidyne on Rh{111}', J. Am. Chem. Soc. 2007,129, 1751-1759
O.R. Inderwildi, S.J. Jenkins, D.A. King
- 'Synergetic effects of the Cu/Pt{110} surface alloy: enhanced reactivity of water and carbon monoxide'. J. Phys. Chem. C 2007, 112, 6422 - 6429
M. J. Gladys, O. R. Inderwildi, S. Karakatsani, V. Fiorin and G. Held
- 'Towards a Comprehensive Model ofthe Synthesis of TiO2 particles from TiCl4'. Ind. Eng. Chem. Res. 2007, 46, 6147 - 6156
R. H. West, M. S. Celnik, O. R Inderwildi, M. Kraft, G. J. O. Beran, W. H. Green
- 'When adding an unreactive metal enhances catalytic activity: NOx decomposition over silver-rhodium bimetallic surfaces'. Surf. Sci. 2007, 601,L103-L108
O.R. Inderwildi, S.J. Jenkins, D.A. King
- 'Dynamic Interplay between Diffusion and Reaction: Nitrogen Recombination on Rh{211}. J. Am. Chem. Soc. 2008, 130, 2213 -2220
O.R. Inderwildi, S.J. Jenkins, D.A. King
- 'Fischer-Tropsch Mechanism Revisited: Altemative Pathways for the Production of Higher Hydrocarbons from Synthesis Gas'. J. Phys. Chem. C2008, 112, 1305 -1307
O.R. Inderwildi, S.J. Jenkins, D.A. King
