Kinetic Implications of Dynamical Changes in Catalyst Morphology during Methanol Synthesis over Cu/ZnO Catalysts
Kinetic Implications of Dynamical Changes in Catalyst Morphology during Methanol Synthesis over Cu/ZnO Catalysts
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DOI：
10.1006/jcat.1997.1629
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发表时间：
1997-06
影响因子：
7.3
通讯作者：
C. V. Ovesen;B. Clausen;J. Schiøtz;P. Stoltze;H. Topsøe;J. Nørskov
中科院分区：
文献类型：
--
作者：
C. V. Ovesen;B. Clausen;J. Schiøtz;P. Stoltze;H. Topsøe;J. Nørskov
本文建立了Cu/ZnO催化剂上甲醇合成反应的动态微观动力学模型。该模型是基于表面科学的测量，它包括动态变化的颗粒形状和活性表面积，最近已被观察到的原位EXAFS测量反应气体的氧化还原电位的变化后发生。有人建议，在粒子形态的变化是有关的Zn-O-Cu界面处的氧空位的数量的变化。此外，还考虑了甲醇合成反应的结构敏感性。动态微观动力学模型被认为是一个更好的描述的动力学测量工作的甲醇催化剂相比，静态微观动力学模型。新模型还解释了瞬态条件下的动力学行为。动态方面被认为是提供了一个基础，为理解在文献中报道的明显冲突的反应顺序。
Abstract In this paper a dynamic microkinetic model of the methanol synthesis reaction over Cu/ZnO catalysts is described. The model is based on surface science measurements and it includes the dynamic changes in particle shape and active surface area which have recently been observed by in situ EXAFS measurements to take place upon change in the redox potential of the reaction gas. It is suggested that the change in particle morphology is related to a change in the number of oxygen vacancies at the Zn–O–Cu interface. Furthermore, the structure sensitivity of the methanol synthesis reaction is also taken into account. The dynamic microkinetic model is seen to give a much better description of the kinetic measurements over a working methanol catalyst compared to a static microkinetic model. The new model also gives an explanation of the kinetic behavior during transient conditions. The dynamic aspects are seen to provide a basis for understanding the apparently conflicting reaction orders reported in the literature.