Chaotic dynamics in the three-variable kinetic model of CO oxidation on platinum group metals
Chaotic dynamics in the three-variable kinetic model of CO oxidation on platinum group metals
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DOI：
10.1016/j.cej.2009.02.017
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发表时间：
2009-11
影响因子：
15.1
通讯作者：
E. Lashina;N. Chumakova;G. Chumakov;A. Boronin
中科院分区：
文献类型：
--
作者：
E. Lashina;N. Chumakova;G. Chumakov;A. Boronin
本文提出了一个简单的三变量等温条件下CO在金属催化剂上氧化的动力学模型，并对反应速率的混沌动力学进行了数值研究。有人建议，在某些浓度的吸附氧，表面改性发生和吸附氧的反应能力的变化，使吸附物种之间的相互作用的活化能急剧增加。此外，氧原子可以渗透到表面下催化剂层中。当表面氧浓度达到某一临界值时，催化剂表面发生重构，氧吸附的概率急剧下降。在此基础上，建立了一个具有特征时间层次结构和一个慢变量的铂族金属上CO氧化的三变量动力学模型。为了研究该模型的动力学性质，考虑了具有快变量的单参数双变量子系统族，研究了这些子系统的稳态和周期解.描述的条件下，该模型的动力学变得混乱的级联倍周期分岔或由于复杂的多峰振荡。
The paper addresses the development of a simple three-variable kinetic model of CO oxidation on metallic catalysts under isothermal conditions and the numerical study of chaotic dynamics of the reaction rate. It is suggested that, at some concentrations of the adsorbed oxygen, a surface modification occurs and the reaction capability of adsorbed oxygen changes, so that the activation energy of the interaction between the adsorbed species increases sharply. Moreover, oxygen atoms can penetrate into the subsurface catalyst layer. At some critical values of the subsurface oxygen concentration, the catalyst surface reconstructs and the probability of oxygen adsorption decreases sharply. Based on these suggestions, a three-variable kinetic model of CO oxidation on the metals of the platinum group is developed, which has the hierarchy of characteristic times and one slow variable. For the purpose of studying the dynamics of the model, the one-parameter family of two-variable subsystems with fast variables is considered, and the steady states and periodic solutions of these subsystems were investigated. The conditions are described under which the dynamics of the model becomes chaotic by means of a cascade of period-doubling bifurcations or owing to complex multipeak oscillations.