Hoenicke GL, Figueiredo W
Departamento de Fisica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, Santa Catarina, Brazil.
Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 2000 Nov;62(5 Pt A):6216-23. doi: 10.1103/physreve.62.6216.
A random distribution of inert sites is introduced in the Ziff-Gulari-Barshad model to study the phase transitions between active and poisoned states. The adsorption of CO and O2 molecules is not possible at the position of the inert sites. This model is investigated in the site and pair approximations, as well as through Monte Carlo simulations. We determine the mean coverages of the elements as a function of the dilution and show that the continuous transition between the active and O-poisoned states is slightly affected by moderate values of dilution in the pair approximation and in the simulations. On the other hand, from the analysis of the hysteresis curves, the transition between the active and CO-poisoned states changes from first order to continuous as one increases the concentration of inactive sites. The observed transition in the site and pair approximations is always of first-order nature. We also found the lines of transition and spinodal points as a function of the concentration of inert sites. Finally, the production rate of CO2 is calculated as a function of the dilution of sites.
在齐夫-古拉瑞-巴沙德模型中引入惰性位点的随机分布，以研究活性态和中毒态之间的相变。在惰性位点处，CO和O2分子无法吸附。该模型在位点近似和对近似下进行了研究，同时也通过蒙特卡罗模拟进行了研究。我们确定了各元素的平均覆盖度作为稀释度的函数，并表明在对近似和模拟中，活性态和O中毒态之间的连续转变受适度稀释值的影响较小。另一方面，通过对滞后曲线的分析，随着无活性位点浓度的增加，活性态和CO中毒态之间的转变从一级转变为连续转变。在位点近似和对近似中观察到的转变始终具有一级性质。我们还发现了转变线和旋节线点作为惰性位点浓度的函数。最后，计算了CO2的生成速率作为位点稀释度的函数。
