用于金属催化剂表征的微量热研究进展

Recent advances in microcalorimetric studies for the characterization of metal based catalysts

催化反应过程伴随着气体分子与催化剂活性中心之间键的形成与转化,并以热量的形式表现出来.采用Tian-Calvet型微量热量计测量这些热量,则可能从能量角度研究气体分子在催化剂表面上的吸附与反应行为,为探索催化剂反应性能及机理提供依据.微量热量计与真空系统相结合的吸附量热技术已经广泛用于催化研究.本文总结了近十年来吸附量热技术在金属催化剂研究中的应用,阐述了这种技术在活性中心表征和反应性能关联方面的研究进展.此外,还介绍了我们研究组发展的脉冲量热装置进行催化反应过程研究的最新进展.

The heat evolved during a catalytic reaction is related to the energy of formation and conversion of chemical bonds between a solid catalyst and the reacting gas molecules. Thus, the measurements and studies for the heat using a Tian-Calvet heat flux microcalorimeter is of primary importance in catalysis. Such studies lead to an understanding of the adsorption and reaction behavior from the point of view of energetics, and give insight into the catalytic properties of catalysts and the mechanisms of catalytic reaction. Microcalorimeter combined with a vacuum system has been widely used to measure the adsorption heat with which probe molecules adsorb on solid catalyst surface. This paper will review the progress of microcalorimetry studies for the metal catalysts over the past ten years, especially in the characterization of active sites and the relationship between adsorption heat and reaction activities. In addition, we develop a pulse calorimetry system for the studies of catalytic reaction. The latest development for the catalytic reaction studies using this technique will also be reviewed in this paper.