引入SiO2对固体超强酸S2O82-/SnO2结构及催化性能的影响

在S2O82-/SnO2中引入SiO2制备了固体超强酸催化剂S2O82-/SnO2-SiO2，利用FT-IR，TG，BET，XRD，UV等分析手段研究了SiO2的引入对S2O82-/SnO2超强酸表面结构及酸量的影响，并通过季戊四醇与苯甲醛的双缩醛反应考察了其催化活性。FT-IR和UV结果表明，引入适量的SiO2可以有效促进催化剂表面锡与过硫酸根的结合，提高催化剂表面的酸量；BET结果表明，引入SiO2可以显著提高样品的比表面积。催化剂S2O82-/SnO2-SiO2的较佳制备条件为：SnO2与SiO2质量比为1，过硫酸铵浸渍液浓度为1.0 mol/L，焙烧温度500 ℃。将催化剂应用于季戊四醇与苯甲醛的双缩醛反应中，双缩醛产率可达89.7%

THE EFFECT OF ADDING SILICA ON THE STRUCTURE AND CATALYTIC PROPERTY OF SOLID SUPERACID S2O2-8/SnO2

A solid superacid S2O82-/SnO2-SiO2 was prepared by the method of precipitation-impregnation. The solid samples were characterized by FT-IR, BET, TG, UV and XRD techniques, and the diacetal reaction activity of pentaerythritol and benzaldehyde over the prepared catalyst samples was evaluated. The characterization results indicated that the addition of SiO2 to SnO2 could promote the combination of S2O82- with Sn, and thus the specific surface area and acidity of the catalyst were increased. The optimum conditions of catalyst preparation were as follow: a SnO2/SiO2 mass ratio of 1, a (NH4)2S2O8 steeping concentration of 1 mol/L and a calcination temperature of 500 ℃. Using catalyst prepared under such conditions to the diacetal reaction of pentaerythritol and benzaldehyde, the yield of diacetal reached 89.7%.