活性组分在载体表面的分散状态  

The dispersion of the active component on the surface of the carrier

作　　者：邓存[1] 

机构地区：[1]宁德师范高等专科学校化学系,福建宁德352100

出　　处：《宁德师专学报（自然科学版）》2006年第4期337-343,共7页Journal of Ningde Teachers College(Natural Science)

摘　　要：许多催化剂的活性组分可在载体表面自发分散.XRD,LRS和XPS等技术可用于研究活性组分在载体表面的分散状态,并测得相应的分散阈值.结果表明,当活性组分含量低于其分散阈值时,它在载体表面呈单层但非密置单层分散,逾此阈值时出现晶相.自发分散效应可以称为自发单层分散原理,这一自发单层分散原理可用于解释和改进多相催化剂制备工艺条件、解决相关的表面结构问题.The active component （e. g. salts and oxides of transition metals）of many catalysts will disperse spontaneously onto the surface of the carrier. Technigues of XRD, LRS and XPS, etc. were employed in examining the dispersion of the active component on the surface of the carrier, and the relevant dispersion thresholds （ i. e. the experimental maximum dispersion capacity） were measured. The results provide evidence that when the active component content is less than the threshold of the active component dispersed on the surface of the carrier, it forms a monolayer, hut not a close - packed monolayer distribution ; above the threshold the crystalline active component appears. The effect of spontaneous dispersion may he characterized with principles of the spontaneous monolayer distribution, the principles of the spontaneous monolayer distribution may be used to improving and understanding the preparative procedures for heterogeneous catalysts or to solving relevant problems of the surface structure.

关 键 词：活性组分 分散状态 XRD 分散阈值 自发单层分散原理 应用 

分 类 号：O643.37[理学—物理化学]