作　　者： ; ; ; ;

机构地区： 肇庆学院化学化工学院轻工化学系

出　　处： 《化学世界》 2007年第1期1-4,9,共5页

摘　　要： 采用共沉淀法制备了固体超强酸SO42-/SnO2-Al2O3。通过XRD、BET、FT IR、TG等手段对其结构进行了表征,将其用于苯甲醚的苯甲酰化反应初步研究了其催化性能。XRD结果表明,在催化剂最佳性能的活化温度500℃时,样品结晶不完全,随着锡铝原子摩尔比的增加,表面主要显现四方晶型的二氧化锡:在锡铝摩尔比为9∶1时,随着活化温度的提高,结晶逐渐趋于完善,结合FTIR结果可知,在700℃以上样品表面结合硫酸根已基本分解完毕。BET结果表明,引入铝可以增加SO42-/SnO2的比表面积,随着活化温度的提高,样品的比表面积呈现先上升后下降的趋势,在最佳性能活化温度时达到最大值。FT IR结果显示,表面硫酸根是以螯合和桥式两种方式和锡配位结合,但是起催化活化中心的大部分是和硫酸根以螯合双齿结合的锡。 Solid superacid SO4^2-/SnO2-Al2O3 was prepared by coprecipitation method. The different samples were characterized by XRD, BET, FT IR and TG analysis methods. The XRD result showed that when the calcination temperature was 500℃, with the addition of Sn imperfect tetragonal SnO2 appeared on the samples surface gradually. When the calcination temperatures increased, the crystal of tetragonal SnO2 appeared gradually. By analysis of FT IR spectra, we know that on the solid surface SO4^2- was combined with Sn through chelate and bridge bond, but the Sn combined with SO4^2- by chelate bond was the main catalytic center. BET results showed that the specific surface area of SO4^2-/SnO2-Al2O3 was larger than SO4^2-/SnO2. Increasing the calcination temperature the specific surface area of the sample was increased before 500℃ and then decreased.In acylation of anisole and benzenecarbonyl chloride,the catalytic properties of SO4^2-/SnO2-Al2O3 was related with its surface area when the calcination temperature was 500℃ ,the atomic ratio of Sn to Al was 9：1 and the concentration of H2SO4 was 3 mol/L the catalyst displayed the best catalytic property.

关 键 词： 固体超强酸 氧化锡 表征

领　　域： [理学] [理学]