关键词: 固体超强酸, 氧化锡, 氧化硅, 表征, 分析方法, 过硫酸铵, 制备

Abstract: 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%.

Key words: Solid superacid, Tin oxide, Silicon dioxide, Characterization, analytical method, ammonium persulfate, preparation