摘要
钯和钒的氧化物是乙烯部分氧化制乙醛、乙酸的很好的催化剂。一些工作已证明微量Pd氧化物的添加起关键作用。本文采用稳定流动条件下的程序升温还原法(TPR)及程序升温再氧化法(TPO)测定了不同Pd含量催化剂的氧化还原能力,借助红外光谱法考查了氧化还原过程中催化剂某些成分的变化,讨论了反应机理。
Oxidation-reduction properties of Pd-V oxides supported on SiO_(2) have been studied by TPR-TPO technique. The change in the structure of some components during the reduction-oxidation process has also been measured by IR-spectroscopy. The results indicate that a very small amount of Pd may lead to a significant decreasing in the reduction temperature of V_(2)O_(5). The reduction temperature of the catalysts decreased with the increasing of Pd content, but the reoxidation temperature of the reduced catalysts don’t change when the Pd-content varies. The oxidation temperature and the reduction temperature of the catalyst close with each other, when the content of PdO is 0.05%. So author concludes that the catalyst with Such a component is the most profitable for the above oxidation reaction. Two consecutive stages in ethylene oxidation were observed, one of them is a stage of adsorptive activation of ethylene and the second is astage of oxidation of ethylene. The reoxidation of reduced catalysts follows also two stages (at 170-260℃ and 360-400℃ respectively). The first stage refers to trapping pro.cess of oxygen in unchanged crystalline phase, and the second stage to the regeneration ,of the deactivited catalysts.
作者
吴志芸
Wu Zhiyun(Department of chemistry,Jilin University,Changchun)
出处
《高等学校化学学报》
SCIE
EI
CAS
1983年第3期392-394,共3页
Chemical Journal of Chinese Universities
