摘要
用ＸＲＤ、ＴＧ－ＤＴＧ、ＳＥＭ和化学分析等手段研究了浸渍Ｈ_２ＳＯ_４的无定形ＴｉＯ２和Ｆｅ_２Ｏ_３在焙烧过程中的晶化、相变、失水及失硫情况，总结出ＳＯ４２－／ＭｘＯｙ型固体超强酸具有与ＳＯ４２－／ＺｒＯ２体系相同的形成规律；用ＩＲ光谱和常温正戊烷异构化反应对ＳＯ４２－／ＴｉＯ２和ＳＯ４２－／Ｆｅ_２Ｏ_３的超强酸性进行了表征，表明它们与／ＺｒＯ_２体系具有相似的表面酸位结构，无水状态主要为Ｌ酸位，吸水后部分Ｌ酸位可转变为Ｂ酸位，但这两种体系的超强酸性均比ＳＯ４２－／ＺｒＯ_２弱，其Ｈ０大约在－１３～－１４之间．
The crystallization,phase transition,dehydration and desulfuration of amorphous TiO2 and Fe2O3 impregnated with H2SO4 during calcination were studied by using XRD,TG-DTG,SEM and chemical analysis methods.Comparing the experimental results with that of SO42-/ZrO2,it was concluded that the regularity of formation of all types of SO42-/MxOy superacids is similar.The superacidity of the SO42-/TiO2 and/Fe2O3 sampleswas charac terized by IR spectroscopy and n-pentane isomerization reaction at ambient temperature.Their acid site structure is the same as that of SO42-/ZrO2.For the dehydrated samples the main acid sites are Lewis type acid sites, which may be transformed into Bronsted type acid sites when the samples are partially hydrated.The superacidity of SO42-/TiO2 and SO42-/Fe2O3 is weaker than that of SO42-/ZrO2,their acid strength H0 is estimated in the range of -13─ -14.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
1994年第6期873-877,共5页
Chemical Journal of Chinese Universities
基金
国家基础研究重大课题
中国石油化学工业总公司资助
关键词
超强酸
固体
酸位结构
硫酸
TiO2,/Fe2O3,Superacid,Regularity of formation,Acid site structure
