摘要
采用改性技术和浸渍-沉淀法制备出纳米固体超强酸催化剂S2O8^2-／ZrO2-Al2O3.通过正交试验获得催化剂制备的最佳条件，即ω（Al2O3）为2．0％，-15℃陈化24h，浸渍液（NH4）2S2O8浓度为0．8mol／L，焙烧温度为650℃：赔烧时间为3h。用XRD、TEN、BET、TG-DTG和化学分析等手段分析了S2O8^2-／ZrO2-Al2O3的晶仡避程、比表面积、含硫量和热稳定性，分析结果表明这四个方面对催化剂的酸性有较大影响。500～650℃焙烧温度下制备的催化剂属纳米材料（〈41nm），有较大比表面积和较好的热稳定性。以优化的催化剂S2O8^2-／Z4O2-Al2O3用于催化合成丁酸异丁酯的最佳条件为：n（异丁醇）：n（丁酸）=1．8：1．0，催化剂用量为，1.0g（以0．3mol丁酸为准），脱水剂环己烷用量为10mL，反应时间为3．0h，催化剂重复使用8次后酯化率仍在90％以上，该催化剂具有催化活性高、不污染环境、可重复使用等特点。
Nanometer composite sohd superacid catalyst S2O8^2-/ZRO2 -Al2O3 was prepared by modified technology and impregnation -precipitation methods. The optimum preparation conditions were determined by orthogonal test ：to（ Al2O3% ）2. 0% ,ageing temperature - 15℃, ageing time 24h, the concentration of （ NH4 ）2S2O8 0. 8mol/L , activated tempereature 650℃, activated time 3h. The crystallo - process , specific surface area , sulphur content and thermal stability of the S2O8^2-/ZrO2 - Al2O3 system have been studied with the method of XRD,TEM,BET ,TG - DTG and the chemical analysis,the result of which indicates that the four factors had more effect with acid strengths of solid superacid catalysts. The catalysts were nanometre materials activated temperature between 500℃ and 650℃,which had large specific surface area and good thermal stability. The optimum synthetic conditions of isobutyl butyrate were resulted as follows ： the molar retio of isobutyl alcohol to buthl acid was 1.8 ： 1.0,mass of the catalyst was 1.0g （ when buthl acid was 0. 3 mol ） ,the volume of the water removing reagent cyclohexane was 10 mL, and the reaction time was 3. Oh. The catalyst exhibited good stability and the conversion of buthl acid still amounted to 90% after 8 runs. The catalyst had the features of highly activated , non - polluting and reusable.
出处
《化学研究与应用》
CAS
CSCD
北大核心
2008年第2期132-137,共6页
Chemical Research and Application
基金
陕西省教育厅自然科学专项基金(05JK135)项目资助
上海市自然科学重点研究项目基金((04)-03F202)项目资助
