CO-oxidation model with superlattice ordering of adsorbed oxygen. I. Steady-state bifurcations James, E. Song, C. Evans, James Evans, James
dc.contributor.department Ames Laboratory
dc.contributor.department Mathematics 2018-02-17T12:02:00.000 2020-06-30T06:00:34Z 2020-06-30T06:00:34Z Fri Jan 01 00:00:00 UTC 1999 1999-10-01
dc.description.abstract <p>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 <em>exact</em> 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.</p>
dc.description.comments <p>The following article appeared in <em>Journal of Chemical Physics</em> 111, 14 (1999): 6579 and may be found at doi:<a href="" target="_blank">10.1063/1.479949</a>. </p>
dc.format.mimetype application/pdf
dc.identifier archive/
dc.identifier.articleid 1026
dc.identifier.contextkey 8091528
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath math_pubs/29
dc.language.iso en
dc.source.bitstream archive/|||Fri Jan 14 23:13:18 UTC 2022
dc.source.uri 10.1063/1.479949
dc.subject.disciplines Biological and Chemical Physics
dc.subject.disciplines Mathematics
dc.title CO-oxidation model with superlattice ordering of adsorbed oxygen. I. Steady-state bifurcations
dc.type article
dc.type.genre article
dspace.entity.type Publication
relation.isAuthorOfPublication ccb1c87c-15e0-46f4-bd16-0df802755a5b
relation.isOrgUnitOfPublication 25913818-6714-4be5-89a6-f70c8facdf7e
relation.isOrgUnitOfPublication 82295b2b-0f85-4929-9659-075c93e82c48
Original bundle
Now showing 1 - 1 of 1
556.91 KB
Adobe Portable Document Format