摘要
通过沉淀-浸渍法制备了一系列金属离子(Ni^(2+),Co^(2+),Fe^(3+))改性的SO_4^(2-)/SnO_2固体超强酸(SS)。利用BET、FT-IR、XRD、TGA等测试技术对固体超强酸进行表征。以乙酸和正丁醇的酯化反应为探针反应,考察了固体超强酸催化剂的催化活性。结果表明:引入金属离子后使SnO_2衍射峰强度降低,晶粒减小,比表面积增大,从而使活性增加。TG-DTA结果表明金属离子的引入,有利于提高催化剂的热稳定性,Ni^(2+)改性的催化剂较Co^(2+),Fe^(3+)改性的催化剂的热稳定性更好,可以较好地稳定活性组分SO_4^(2-),使其高温分解流失趋势变得更缓和。制备Ni/SO_4^(2-)-SnO_2最优条件为焙烧温度为500℃,镍离子浓度为0.5mol/L。
A series of sulfated tin oxide SO_4^（2-）/SnO_2（SS）modified with different metal ions were prepared by impregnation and deposition method.The solid superacids were characterized by BET, FT-IR,XRD,and TGA.The catalytic activities for esterification of acetic acid and n-butanol have been investigated.As a result,the introduction of appropriate amount of metallic ions would decrease the diffractions intensity of SnO_2 and thus increase the specific surface area and catalytic activity. TGA showed that thermal stability of catalysts was increased after introducing metallic ions. Meanwhile,intro ducing metallic ions could effectively restrain the loss of SO_4^（2-）.The optimum calcination temperature and concentration of nickel nitrate for SO_4^（2-）/SnO_2 catalyst were 500℃and 0.5 mol·L^（-1）,respectively.
