EFFECT OF LATERAL INTERACTIONS ON THE KINETICS OF THE OXIDATION OF CARBON-MONOXIDE ON PALLADIUM

Monte Carlo simulations are used to study the effect of lateral repuls ion between CO molecules on the kinetics of the oxidation of CO and O- 2 on a Pd catalyst. The results of CO coverage and reaction rate are c ompared using three models of lateral interaction: (i) short-range lat eral interaction (nearest neighbors); (ii) long-range lateral interact ion (dipole-dipole type); and (iii) lateral interaction energy equal t o beta theta(CO) mean field approximation (MFA). The results show that the MFA model predicts reaction rates and CO coverage higher than oth er models. However, the disagreement is significantly less between the MFA model and the long-range lateral interaction model. The results m ay be interpreted in terms of the different topography of the adsorbed CO phase that is generated when using the various models.