Regensburg 2004 – wissenschaftliches Programm
O 20.4: Vortrag
Dienstag, 9. März 2004, 12:00–12:15, H45
CO oxidation at RuO2(110) studied by first-principles kinetic Monte-Carlo simulations — •Karsten Reuter1,2, Daan Frenkel2, and Matthias Scheffler1 — 1Fritz-Haber-Institut, Berlin — 2AMOLF, Amsterdam
A quantitative modeling of catalytic activity requires a high accuracy in the description of each of the manifold of involved elementary processes, as well as a correct statistical mechanics treatment of the interplay between them. We attempt such a modeling by first-principles kinetic Monte-Carlo simulations, i.e. using rates derived from density-functional theory as input. Modeling the CO oxidation over RuO2(110) we obtain a full (T,pO2,pCO) turnover frequency diagram, which agrees with available experimental data. The surface configurations actuating catalysis are found to be strongly influenced by kinetic effects, most prominently under gas phase conditions where the system is close to a surface phase transition. The highest steady-state turnover rates are obtained for the resulting phase coexistence at the surface, which enables specific reaction mechanisms that do not operate at other temperature and pressure conditions including ultra-high vacuum.