We analyze a model for CO oxidation on surfaces which incorporates both rapid diffusion of adsorbed CO, and superlattice ordering of adsorbed immobile oxygen on a square lattice of adsorption sites. The superlattice ordering derives from an “eight-site adsorption rule,” wherein diatomic oxygen adsorbs dissociatively on diagonally adjacent empty sites, provided that none of the six additional neighboring sites are occupied by oxygen. A “hybrid” formalism is applied to implement the model. Highly mobile adsorbed CO is assumed randomly distributed on sites not occupied by oxygen (which is justified if one neglects CO–CO and CO–O adspecies interactions), and is thus treated within a mean-field framework. In contrast, the distribution of immobile adsorbed oxygen is treated within a lattice–gas framework. Exact master equations are presented for the model, together with some exact relationships for the coverages and reaction rate. A precise description of steady-state bifurcation behavior is provided utilizing both conventional and “constant-coverage ensemble” Monte Carlo simulations. This behavior is compared with predictions of a suitable analytic pair approximation derived from the master equations. The model exhibits the expected bistability, i.e., coexistence of highly reactive and relatively inactive states, which disappears at a cusp bifurcation. In addition, we show that the oxygen superlattice ordering produces a symmetry-breaking transition, and associated coarsening phenomena, not present in conventional Ziff–Gulari–Barshad-type reaction models.
Skip Nav Destination
Article navigation
8 October 1999
Research Article|
October 08 1999
CO-oxidation model with superlattice ordering of adsorbed oxygen. I. Steady-state bifurcations
E. W. James;
E. W. James
Ames Laboratory and Department of Mathematics, Iowa State University, Ames, Iowa 50011
Search for other works by this author on:
C. Song;
C. Song
Ames Laboratory, Iowa State University, Ames, Iowa 50011
Search for other works by this author on:
J. W. Evans
J. W. Evans
Ames Laboratory and Department of Mathematics, Iowa State University, Ames, Iowa 50011
Search for other works by this author on:
J. Chem. Phys. 111, 6579–6589 (1999)
Article history
Received:
April 07 1999
Accepted:
July 14 1999
Citation
E. W. James, C. Song, J. W. Evans; CO-oxidation model with superlattice ordering of adsorbed oxygen. I. Steady-state bifurcations. J. Chem. Phys. 8 October 1999; 111 (14): 6579–6589. https://doi.org/10.1063/1.479949
Download citation file:
Sign in
Don't already have an account? Register
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
Pay-Per-View Access
$40.00
Citing articles via
DeePMD-kit v2: A software package for deep potential models
Jinzhe Zeng, Duo Zhang, et al.
Related Content
Dynamic response of an irreversible catalytic reaction to periodic variation of the reactant’s pressure
J. Chem. Phys. (February 2000)
Adsorption mechanisms and surface heterogeneity in the oxidation reaction of CO
J. Chem. Phys. (October 1998)
Mean-field hierarchical equations for some A+BC catalytic reaction models
J. Chem. Phys. (October 1998)
Influence of the interaction on oscillatory behavior in a surface reaction model
J. Chem. Phys. (November 1998)