SO_4^(2-)/ZrO_2-SBA-15催化剂合成条件研究

Study on synthesis conditions of SO_4^(2-)/ZrO_2-SBA-15

以介孔分子筛SBA-15为载体,利用溶胶-凝胶法,在SBA-15的合成过程中引入活性组分SO42-/ZrO2,得到了含有SO42-/ZrO2的SBA-15介孔固体酸催化剂SO42-/ZrO2-SBA-15。以乙酸正丁酯的合成为探针反应,考察了SO42-/ZrO2的合成条件及负载型催化剂SO24-/ZrO2-SBA-15合成条件对催化剂催化活性的影响。确定催化剂的合成条件为:m(模板剂)∶m(去离子水)∶m[盐酸(质量分数为36%)]∶m(正硅酸乙酯)∶m(八水氧氯化锆)=4.0∶98.0∶25.1∶8.48∶5.6;搅拌温度为40℃;加入硅源,搅拌20 h后,加入八水氧氯化锆;焙烧温度为650℃;硫酸溶液的浓度为3 mol/L。负载型催化剂制备过程中,滴加氨水后最佳的pH为9~10,在介孔分子筛合成过程中引入超强酸所得的催化剂活性最高。

Sol-gel method was used in experiment and SO2-4/ZrO2 was introduced during synthesis process of mesoporous molecular sieve SBA-15.SO2-4/ZrO2-SBA-15 mesoporous solid acid catalyst was synthesized with SBA-15 as supporter and with SO2-4/ZrO2 as active constituent.With the synthesis of n-butyl acetate as probe reaction,influences of synthesis conditions for SO2-4/ZrO2 and supported SO2-4/ZrO2-SBA-15 catalyst on catalytic activity were investigated. Synthesis conditions of catalyst were confirmed as follows： m（template） ： m（deionized water） ： m（HCl,mass fraction of 36% ） ： m （ tetraethyl orthosilicate ） ： m （ ZrOCl2·8H2O） = 4. 0： 98.0：25.1： 8.48：5.6 ; stirring temperature was 40 ℃ ; added silica source at first, then added ZrOCl2· 8H2O after stirring for 20 h;calcination temperature was 650℃ ;and concentration of sulfuric acid was 3 mol/L. In synthesis process of supported catalyst the optimum pH value should be at 9 - 10 after adding ammonia and the catalyst that introducing supper acid in systhesis process of mesoporous molecular sieve had the best catalytic activity.