scispace - formally typeset
Journal ArticleDOI: 10.1016/0009-2614(94)87085-3

Cellular automata modelling of a surface catalytic reaction with Eley-Rideal step: the case of CO oxidation

05 Aug 1994-Chemical Physics Letters (North-Holland)-Vol. 225, Iss: 4, pp 303-308
Abstract: Cellular automata (CA) rules for a model surface reaction with Eley-Rideal step (exemplifying CO oxidation) have been formulated The CA simulations corroborate the earlier known Monte Carlo (MC) simulation results and show qualitative and near quantitative resemblance The results are analyzed and discussed in the light of MC and mean field solutions

...read more

Topics: Monte Carlo method (56%), Cellular automaton (53%)
Citations
  More

Journal ArticleDOI: 10.1063/1.3262306
Abstract: We study the effect of coadsorption of CO and O on a Ziff–Gulari–Barshad model with CO desorption for the reaction CO+O→CO2 on a catalytic surface. Coadsorption of CO at a surface site already occupied by an O is introduced by an Eley–Rideal-type mechanism that occurs with probability p, 0≤p≤1. We find that besides the well-known effect of eliminating the second-order phase transition between the reactive state and an O-poisoned state, the coadsorption step has a profound effect on the transition between the reactive state and the CO-poisoned state. The coexistence curve between these two states terminates at a critical value kc of the desorption rate k, which now depends on p. Our Monte Carlo simulations and finite-size scaling analysis indicate that kc decreases with increasing values of p. For p=1, there appears to be a sharp phase transition between the two states only for k at (or near) zero.

...read more

Topics: Desorption (51%)

14 Citations


Journal ArticleDOI: 10.1016/J.APSUSC.2009.01.073
A. K. Mukherjee1, Indrajit Sinha1Institutions (1)
Abstract: The effect of periodic variation of external pressure on the catalytic oxidation of CO is simulated for a modified Ziff–Gulari–Barshad (ZGB) model including the Eley–Rideal (ER) step. The external CO partial pressure is periodically varied between its values in reactive and CO poisoned states. The results show different amplitudes of such perturbation significantly influence the CO2 production rate. Latter also changes with the period of such oscillations, especially for perturbations with larger amplitudes. However, for a given period there is a critical value of the amplitude above which, the catalyst surface becomes irreversibly poisoned.

...read more

10 Citations


Journal ArticleDOI: 10.1063/1.3262306
Abstract: We study the effect of coadsorption of CO and O on a Ziff-Gulari-Barshad (ZGB) model with CO desorption (ZGB-d) for the reaction CO + O --> CO_2 on a catalytic surface. Coadsorption of CO on a surface site already occupied by an O is introduced by an Eley-Rideal-type mechanism that occurs with probability p, 0 <= p <= 1. We find that, besides the well known effect of eliminating the second-order phase transition between the reactive state and an O-poisoned state, the coadsorption step has a strong effect on the transition between the reactive state and the CO-poisoned state. The coexistence curve between these two states terminates at a critical value k_c of the desorption rate k which now depends on p. Our Monte Carlo simulations and finite-size scale analysis indicate that k_c decreases with increasing values of p. For p=1, there appears to be a sharp phase transition between the two states only for k at(or near) zero.

...read more

Topics: Desorption (51%)

10 Citations


Open accessJournal ArticleDOI: 10.1007/S10955-011-0414-5
Indrajit Sinha1, A. K. Mukherjee1Institutions (1)
Abstract: Using kinetic Monte Carlo simulations, we study the effect of oscillatory kinetics due to surface reconstructions on Ziff-Gulari-Barshad (ZGB) model discontinuous phase transition. To investigate the transition, we do extensive finite size scaling analysis. It is found that the discontinuous transition still exists. On inclusion of desorption in the model, the order-parameter probability distribution broadens but remains bimodal. That is, the first-order phase transition becomes weaker with increase in desorption rate.

...read more

8 Citations


Journal ArticleDOI: 10.1088/0256-307X/19/4/326
Abstract: The effect of the coadsorption of CO and O2 on the Ziff-Gulari-Barshad surface catalytic reaction system is studied by Monte Carlo simulation. The coadsorption of both species adds an extra reaction step to the classical Ziff-Gulari-Barshad model. It is shown that the second-order phase transition from the reactive state to the O-passivated state in the Ziff-Gulari-Barshad model is eliminated, and the production rate of CO2 increases linearly along the fraction yco of CO in gas phase when it is low, in agreement with experimental results. We also find that the increase of the probability of the coadsorption leads to the decrease of the critical value of yco of the discontinuous phase transition to the CO-passivated state.

...read more

Topics: Phase transition (50%)

7 Citations


References
  More

Journal ArticleDOI: 10.1103/PHYSREVLETT.56.2553
Abstract: An irreversible kinetic surface-reaction model, based upon the reaction of carbon monoxide and oxygen on a catalyst surface, is presented. It is found by computer simulation that the adsorbed molecules on the surface undergo both first- and second-order kinetic phase transitions. These transitions correspond to the "poisoning" phenomenon seen on catalysts. Interesting transient and periodic behavior is also seen.

...read more

Topics: Phase transition (51%)

770 Citations


Book ChapterDOI: 10.1016/S0360-0564(08)60133-9
T. Engel1, Gerhard Ertl1Institutions (1)
Abstract: Publisher Summary Catalytic oxidation of carbon monoxide over catalysts from the platinum group metals has been investigated. Apart from its enormous practical importance, this reaction is considered to proceed through a relatively simple mechanism because only diatomic molecules are involved and product formation occurs presumably only over a very few steps. This chapter discusses the adsorptive properties of the reactants, their mutual interaction, and the mechanism and kinetics of product formation as well as the investigations with well defined single-crystal surfaces. The activity of a catalyst for a particular reaction is strongly dependent on the surface structure. Directive investigation of the influence of the surface structure on the catalytic activity was performed by using a platinum single crystal whose surface was curved in such a way that not only the plane but also vicinals with varying step density of two different crystallographic directions were present.

...read more

Topics: Platinum (56%), Catalysis (55%), Catalytic oxidation (53%) ...read more

484 Citations


Journal ArticleDOI: 10.1080/03602457708081723
Moshe Sheintuch1, H. A. Schmitz1Institutions (1)
Abstract: This paper deals with the status of knowledge concerning open catalytic reaction systems which, though exposed to constant conditions, exhibit sustained oscillatory states. Such behavior arouses in...

...read more

Topics: Catalysis (52%)

204 Citations


Journal ArticleDOI: 10.1016/0021-9517(75)90278-X
E Mccarthy1Institutions (1)
Abstract: Supported Pt catalyzed oxidation of CO was studied as a function of sintering severity. Specific rate data (moles CO oxidized/time · area of Pt) indicate the reaction to be demanding at low CO concentration and facile at higher CO concentrations. Further, sustained isothermal oscillations were observed. Overall kinetic behavior and the oscillations can be rationalized by viewing the oxidation process as one consisting of (a) an Eley-Rideal mechanism involving gaseous CO reacting with adsorbed O 2 at low CO concentrations, and (b) chemisorption of O 2 upon a surface partially covered with CO at higher CO concentrations. Global sintering kinetics in air are found to be second order in surface area with an activation energy of about 60 kcal.

...read more

Topics: Chemisorption (52%)

165 Citations


Journal ArticleDOI: 10.1063/1.453570
Abstract: A simple model for heterogeneous catalysis, recently introduced by Ziff, Gulari, and Barshad (ZGB), has been explored using computer simulation. This is a nonequilibrium model which exhibits phase transition‐like behavior. The only parameter in this model (Y) sets the ratio with which two reactive species (A and B2) are fed to the surface (lattice). On the square lattice, ZGB found a range of values of this parameter for which steady states with nonzero A and B concentrations occur. Outside of this range, the surface becomes completely covered with A or B sites. The range of Y values corresponding to steady state with nonzero A and B concentrations is bounded by two ‘‘critical’’ values Y1 and Y2. For values of Y close to but above Y1 we have obtained approximate values for the exponents which describe the dependence of the steady‐state densities of A and B sites on (Y−Y1). These exponents both seem to have the same value independent of lattice details. We have extended the work of ZGB to the hexagonal lat...

...read more

Topics: Square lattice (51%), Phase transition (50%)

161 Citations


Performance
Metrics
No. of citations received by the Paper in previous years
YearCitations
20151
20123
20111
20102
20093
20061