AVS 50th International Symposium
    Surface Science Monday Sessions
       Session SS2-MoM

Paper SS2-MoM8
From Atomic Scale Reactant Ordering to Mesoscale Pattern Formation: CO Oxidation on Pd(100)

Monday, November 3, 2003, 10:40 am, Room 327

Session: Catalysis I: Adsorption and Reactions of Small Molecules at Surfaces
Presenter: D.-J. Liu, Iowa State University
Authors: D.-J. Liu, Iowa State University
J.W. Evans, Iowa State University
Correspondent: Click to Email
We successfully connect-the-length-scales from the realistic modeling of reactant ordering in CO+O/Pd(100) to the prediction of mesoscale reaction front propagation. Description of ordering of CO on bridges sites, and O on four-fold hollow sites requires atomistic lattice-gas modeling. Repulsive CO-CO and O-O interactions beyond nearest-neighbor in range must be carefully selected to match experimentally observed ordering. Precise description of reaction-diffusion fronts also requires sophisticated analysis of chemical diffusion of CO which reflects CO-CO interactions and the presence of the coadsorbate. Numerical techniques are developed to analyse both reaction kinetics and diffusion under inhomogenous conditions using realistic lattice gas modeling. The results are then incorporated into a continuous reaction-diffusion equation. Pattern formation problems on the mesoscale, e.g., chemical wave profiles, can then be studied efficiently.