Determining Interactions between Adsorbates on Transition Metals

Abstract

The last couple of years it lias become more and more clear that lateral interactions (interactions between adsorbates) play an important role in the kinetics of surface reactions. We work on the determination of these interactions, and on methods to predict the kinetics including these interactions. Our main method is Dynamic Monte Carlo. With this method we can simulate all reactions on a surface with between 10⁴ and 10⁸ reactive sites for about 10²–10³ seconds. The simulations yield predictions of the kinetics that are exact for a given model of the surface reactions. As input we need rate constants (prefactors and activation energies) and lateral interactions. These are either obtained by fitting to experimental results or by calculating them using Density-Functional Theory. We use Evolutionary Computation methods to vary and optimize the kinetic parameters when fitting to experiments.