摘要
研究了非流动条件下搅拌对B-Z振荡反应的影响。实验发现即使在氮气保护下,搅拌仍对振荡行为(振幅和周期等)有明显影响。为解释搅拌的影响作用,对B-Z反应的Oregonator模型作了修正和补充并依据非平衡态热力学的一般原理将搅拌影响唯象地归结为反应速率常数的相对变化。修正后的模型不仅较好地克服了原模型存在的一些问题,而且在引入搅拌作用以后得到了与实验现象定性一致的数值模拟结果。
The effects of stirring on the oscillations of the ferrion-catalyzed and ceriumcatalyzed B-Z reactions are investigated in the stirred batch reactor. The experimental results show that the oscillatory behavours (period, amplitude etc.) are sensitive to the rate of stirring even in the nitrogen atmosphere and the stirring effects are different for ferrion-catalyzed and cerium-catalyzed reactions. We believe that such stirring effects reflect the interference between chemical reactions and transport processes, The inert salt which does not take part in the reac- tion may also effect the oscillations.Some shortcomings in present theoretical models of B-Z oscillating reaction are discussed. The original Oregonator model which consists of five irreversible steps and involves three intermediates is amplified to six irreversible steps and three intermediates like this: The amplified model eliminates some shortcomings of original models. The results of numerical simulations of the amplified model are qualitatively consistent with experimental results.In principle, there are always certain micro-inhomogeneities in reaction media and some coupling may occur between different irreversible processes, e.g. chemical reactions and transportation, in such anisotropic media. Based on these considerations, the stirring effects on reaction are accounted to be a relative changing of some rate coefficients, and a factor relating stirring effects is added to the amplified model. The numerial results of the amplified model with such a stirring factor are also in qualitative agreement with experiments.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
1989年第1期44-49,共6页
Acta Physico-Chimica Sinica
基金
国家自然科学基金
