摘要
WO_2/钛铝胶系列样品通过浸渍法制备.XRD 和XPS 测定结果表明WO_3单层分散在钛铝胶表面,分散阈值为0.22g WO_3/(100m^2).假定WO_3在钛铝胶表面按照密置单层模型分散,其计算值为0.198g WO_3/(100m^2).表明测定值与理论模型的计算值相接近.LRS测定表明:当WO_3的载量低于0.082g WO_3/(100m^2钛铝胶)时,只有四而体配位的钨存在;当WO_3的载量超过0.082g WO_3/(100m^2钛铝胶)时,钨主要以八面体配位存在.同时,LRS的实验结果也表明,550℃焙烧的WO_3/钛铝胶样品没有Al_2(WO_4)_3生成.对高温焙烧条件下,Al_2(WO_4)_3的生成也进行了研究.
A series of WO_3/titania-alumina samples wasprepared by impregnation method.The results of XRD and XPSshow that WO_3 is dispersed as a monolayer on the surface oftitania-alumina.The dispersion threshold is 0.22gWO_3/(100m^2).(?)t approximately agrees with the value,0.198gWO_3/(100m^2),calculated from the model on assuming that the WO_3 is dispersedas a elose-packed monolayer on titania-alumina surface.WithLRS measurement,it can be found that as the loading of WO_3is lower than 0.082gWO_3/(100m^2 titania-alumina),only distortedtetrahedral coordinated tungsten will he located on the surface,however as the loading of WO_3 is higher than 0.082g WO_3/(100m^2titania-alumina),octahedral coordinated tungsten dominates.LRSmeasurements also show no Al_2(WO_4)_3 is formed as theWO_3/titania-alumina samples were caleined at 550℃.The forma-tion of Al_2(WO_4)_3 at higher temperature also has been studied.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
1993年第1期13-20,共8页
Acta Physico-Chimica Sinica
基金
Projects Supported by the Science Fund of the Chinese Academy of Sciences
关键词
氧化钨
钛铝胶
表面结构
Tungsten oxide
Titania-alumina
Dispersion threshold
Surface structure
LRS
XPS
XRD
