Effects of inert species in the gas phase in a model for the catalytic oxidation of CO.
Phys Rev E Stat Nonlin Soft Matter Phys
; 85(3 Pt 1): 031143, 2012 Mar.
Article
em En
| MEDLINE
| ID: mdl-22587074
We study by kinetic Monte Carlo simulations the catalytic oxidation of carbon monoxide on a surface in the presence of contaminants in the gas phase. The process is simulated by a Ziff-Gulari-Barshad (ZGB) model that has been modified to include the effect of the contaminants and to eliminate an unphysical oxygen poisoned phase at very low CO partial pressures. The impurities can adsorb and desorb on the surface but otherwise remain inert. We find that if the impurities cannot desorb, no matter how small their proportion in the gas mixture, the reactive window and discontinuous transition to a CO poisoned phase at high CO pressures that characterize the original ZGB model disappear. The coverages become continuous, and once the surface has reached a steady state there is no production of CO(2). This is quite different from the behavior of systems in which the surface presents a fixed percentage of impurities. When the contaminants are allowed to desorb, the reactive phase appears again for CO pressures below a value that depends on the proportion of contaminants in the gas and on their desorption rate.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Dióxido de Carbono
/
Modelos Moleculares
/
Transição de Fase
/
Gases
/
Modelos Químicos
Idioma:
En
Revista:
Phys Rev E Stat Nonlin Soft Matter Phys
Assunto da revista:
BIOFISICA
/
FISIOLOGIA
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Venezuela
País de publicação:
Estados Unidos