摘要
本文研究了多晶钯表面上CO脱附动力学,对各种覆盖度的脱附谱图进了划分温区的分析,对低温区首次提出恒定脱附速度的动力学解析.对于多晶钯面上CO的脱附,随脱附温度的升高,脱附反应级数减小而视活化能增加.为解释这种现象提出了活性集团假设,深入研究活性集团的动力学性能将有助于了解脱附过程的动力学特性.
The desorption kinetics of CO from polycrystalline palladium surface was studied by TPD and AES. By a method of data analysis different from those used in the literature, kinetic parameters for low and high temperature ranges were obtained. In the low temperature range ( T<395 K ) the desorption reaction order was higher and the apparent activation energy of desorption was lower than those in the higher temperature range ( 395 K≤T≤430K ) .
An interpretation of this phenomenon is offered as follows. Desorption proceeds via an active ensemble mechanism, that is several molecules are adsorbed together on multiple adsorption center to form an active ensemble in which mutual interaction results in the formation of activated molecules. This activated molecules are the intermediates through which desorption proceeds.
Further study on the kinetic performance of active ensembles would be helpful to understand the kinetic characteristics of the desorption process.
出处
《分子催化》
EI
CAS
CSCD
1989年第3期190-196,共7页
Journal of Molecular Catalysis(China)
基金
国家自然科学基金资助课题
