导　　师： 郭锡坤

学科专业： 081705

授予学位： 硕士

作　　者： ;

机构地区： 汕头大学

摘　　要： 本论文中作者以柠檬酸和正丁醇合成柠檬酸三丁酯（TBC），考察了柠檬酸三 丁酯的酯化合成体系，系统研究了固体超强酸催化剂SO/_4~/(2-/)//TiO/_2在柠檬酸与正丁 醇酯化反应中的催化性能，通过稀土元素Tm的负载来改性制得催化性能优异的 Tm-SO/_4~/(2-/)//TiO/_2催化剂，并且通过催化剂的活性评价和物化性能表征来研究催化剂 结构与性能的关系，为固体超强酸催化合成TBC的工业化提供了有益依据。 作者首先对TBC的酯化体系进行了考察，分别在无催化剂、浓硫酸、自制 固体超强酸催化剂SO/_4~/(2-/)//TiO/_2催化下，研究了柠檬酸三丁酯合成反应中酸转化率、 出水量与反应时间的关系，并在固体超强酸催化剂催化下通过单因素实验对酸醇 比、催化剂用量等酯化反应条件进行了优化。作者以固体超强酸SO/_4~/(2-/)//TiO/_2作催 化剂合成柠檬酸三丁酯，研究该催化剂在柠檬酸与正丁醇酯化反应中的催化活性 和稳定性，考察了SO/_4~/(2-/)促进剂种类与用量、焙烧温度对催化剂结构、性能的影响。 结果表明，在TBC的合成反应中，对于SO/_4~/(2-/)//TiO/_2催化剂，选用（NH/_4）/_2SO/_4作SO/_4~/(2-/) 促进剂较H/_2SO/_4为优；（NH/_4）/_2SO/_4的适宜用量为20％，此时所制得的催化剂具有较 高的催化活性。综合考虑催化剂的活性与选择性，最佳的焙烧温度应为600℃， 此时反应的转化率为92.7％，催化选择性为99％，酯产率达92.3％。催化剂的物相 结构与反应的选择性密切相关，锐钛矿TiO/_2（A）晶相的形成与完善是催化剂针 对此酯化体系选择性提高的关键。在此酯化合成体系中催化剂SO/_4~/(2-/)//TiO/_2的稳定 性不理想，其失活是由于SO Tri-n-butyl citrate/(TBC/) was synthesized with solid super acid as catalyst, and the catalytic properties of the catalyst SO42VTiO2 in esterification of citric acid with n- butanol were studied. A new catalyst Tm-S04/%扵i02 was prepared by modification on which the rare earth element Tm was loaded. The correlation between its structure and properties was also investigated. All these above strongly support the industrialization of TBC synthesis catalyzed by solid super acid. This paper reported the esterification synthesis of TBC under no catalyst, H2S04, or solid super acid SO421TiO2. The correlation between reaction conversion, water yield and reaction time was surveyed. The effects of initial molar ratio and catalyst quantity were investigated and the optimum synthesis conditions were found. Tri-n-butyl citrate was synthesized with solid super acid S042/]T102 as catalyst, and the activity and stability of the catalysts in esterification of citric acid with n-butanol were studied. The effects of /(NH4/)2S04 quantity and calcination temperature on the catalysts were studied and the correlation between their structure and properties was also investigated. The results showed that /(NH4/)2S04 was better than H2S04 as promoter. The catalytic selectivity amounted to 99/% while 20/% /(NH4/)2S04 added and 6000C calcinated. On this condition the conversion of citric acid was 92.7/%, and the ester yield was 92.3/%. The formation and growth of anatase crystalline phase was the key factor in the improvement of catalytic selectivity. The deactivation of catalysts in TBC synthesis resulted from the carbon deposition and the los

关 键 词： 柠檬酸三丁酯 催化酯化 固体超强酸 改性 固体超强酸

领　　域： [理学] [理学] [理学] [理学]