摘要
贵金属钯/炭催化剂(Pd/C)在石油化工和精细化工中有着广泛的用途,受到人们的普遍重视。作者成功地研制出一种性能优良的Pd/C,已用于药物和香料生产过程中的加氢反应。制备Pd/C的过程表明,影响其加氢活性的因素比较复杂,热处理就是其中重要的一环。本文总结了含水55%的Pd/C催化剂在不同气氛中进行热处理后对苯乙烯加氢活性的影响。另外,通过热差法(DTA)和光电子能谱(XPS)
Heat treatment is one of the important catalyst treating processes which significantly affect the catalytic activity of Pd/C catalyst. It was found that the properties of Pd/C catalyst and its activity for styrene hydrogenation varied with heat treatment in various gases. The results showed that the catalytic activity gradually decreases with increasing heating time when the catalyst is heated in air and in steam at 120℃. The temperature at which the activity drops was found above 300℃ in nitrogen and 400℃ in hydrogen. The results from DTA and XPS indicated that the reason which causes the decrease of catalytic activity by heating in air is due to the oxidation of metallic palladium particles into PdOx. When the catalyst is heated at 600℃ ia hydrogen for 6 hours, the catalyst sinters seriously. The metal particle size increases from 75 A to 262 A and the catalyst is completely deactivated. When deactivated catalyst is carefully oxidated in oxidation gases, then reduced in hydrogen,the catalytic activity can be recovered.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
1992年第2期213-218,共6页
Journal of Fuel Chemistry and Technology
关键词
钯
炭
催化剂
热处理
Pd/C catalyst
heat treatment
activity of hydrogenation
