稀土固体超强酸SO42-/TiO2/La3+催化合成丁酸异戊酯

丁酸异戊酯是无色至淡黄色透明油状液体,有近似生梨和香蕉香甜气。天然品存在于椰子油、可可豆、苹果、香蕉、葡萄、草莓等中,是我国ＧＢ２７６０－８６规定允许使用的食用香料,主要用以配制香蕉、菠萝、杏、樱桃和杂锦水果等型香精;也可用作提取天然香料的溶剂、乙酸纤维素的溶剂及增塑剂。通常它是在硫酸催化下由丁酸和异戊醉酯化反应而得［１,２］,反应时间长,副反应多,对设备腐蚀严重,废水排放量大,后处理工艺复杂。为此,本实验选用稀土固体超强酸ＳＯ４２－／ＴｉＯ２／Ｌａ３＋作为催化剂进行某些酸与异戊醇的酯化反应。 …     

固体超强酸SO2-4-MoO3-TiO2的制备及其催化酯化性能研究

In this paper a new solid superacid catalyst SO2-4-MoO3-TiO2 was prepared.The activity of the catalyst in esterification of acetic acid and iso-amyl alcohol was measured and compared with that of SO2-4-TiO2 and MoO3-TiO2.The results showed that SO2-4-MoO3-TiO2 had better catalytic performance than SO2-4-TiO2 and MoO3-TiO2.There was evident coordination between MoO3 and SO2-4 when they coexisted on TiO2.     

稀土固体超强酸SO42-/TiO2/La3+催化合成丁酸异戊酯

The synthesis of isoamyl butyrate with isoamyl alcohol and butyric acid as reactants and rare-earth solid superacid SO₄^2-/TiO₂/La³⁺ as catalyst had been studied.The influent actors of reaction were investigated.The results showed that the appropriate conditions should be: Weight of catalyst was 0.5g (weight of butyric acid if 0.2mol); molar ratio of isoamyl alcohol to butyric acid was 1.8: 1; reaction time was 2.0 h; the taking water reagent (Toluene) was 15mL.The yield of isoamyl butyrate was about 99.0%.     

新型介孔SO4^2-/TiO2固体酸的制备及其催化酯化性能

以无定形高比表面积水合钛酸(H2Ti2O5·xH2O)为载体,采用等体积浸渍法制备了新型晶须状介孔SO42-/TiO2固体酸催化剂,利用X射线衍射、N2吸附-脱附、扫描电镜、红外光谱、热重和氨程序升温脱附等技术考察了催化剂的结构特征和表面酸性及其对乙酸与正丁醇液相酯化反应的催化活性.结果表明,SO42-/TiO2同体酸催化剂不仅具有纳米级晶粒、晶须状形貌、高比表面积和介孔结构,还保持了完善的锐钛矿晶型、较强的酸性和较高的热稳定性;当焙烧温度高于500℃时,催化剂表面结合的SO42-逐渐流失,酸中心数逐渐减少.在m(催化剂)=0.2 g、n(正丁醇)/n(乙酸)=1.5和反应时间3 h条件下,500℃焙烧的催化剂活性最高,正丁醇转化率达94%,乙酸正丁酯选择性为100%,且催化性能和分离沉降性能均优于SO42-/P25催化剂.     

固体超强酸SO4^2——MoO3—TiO2的制备及其催化酯化性能研究

SO4^2--MxOy型固体超强酸自问世以来一直受到人们的广泛关注,已对其进行了大量的研究。该类催化剂的酸度强度高,在烷基化、酰基化、裂解、醇脱水、异构化、酯化等反应中有很高的催化活性。最常用的氧化物基体是ZrO2和TiO2,最后的促进剂SO4^2-。也有用MoO3作促进剂的^[1-3],得到相应的超强酸催化剂。作者在SO4^2--TiO2超强酸的基础上,将MoO3和SO4^2-同时负载在TiO2基体上,得到SO4^2--MoO3-TiO2固体超强酸,以乙酸异戊酯的合成为探针反应考察了该催化剂的催化酯化活性,并与SO4^2--TiO2、MoO3-TiO2的催化酯化活性作了比较。     

催化精馏专用填料型固体酸SO42-/ZrO2-Al2O3-Al的研究

为了研制催化精馏专用催化剂,采用铝阳极氧化法制备了Al2O3-Al一体型载体,并将活性固体超强酸SO42-/ZrO2引入到Al2O3-Al上,得到一种新型催化精馏专用填料式固体酸SO42-/ZrO2-Al2O3-Al催化剂.利用XRD、 SEM、 BET、 XPS、 NH3-TPD等手段对其进行了表征.结果表明,所制得的阳极氧化铝膜厚为56 μm, SO42-/ZrO2-Al2O3-Al固体酸具有比表面积大、酸强度适中的特点.XRD结果表明, ZrO2在Al2O3-Al上处于高度分散状态.将该固体酸用于乙酸/乙醇酯化反应中,显示出较高的催化活性,且稳定性较好.     

固体酸Fe2(SO4)3催化合成丙酸异戊酯

Solid acid ferric sulphate Fe2(SO4)3 was prepared and used for the study of the catalytic synthesis of iso-amyl propionate. The optimun reaction conditions were follows: the ratio of amount of substance n(iso-amylalcohol) : n(propionic acid) = 1.5, the reaction time 2h, the catalyst quantity 1.5g, and dewatering solvent toluene 10ml. The yield was 97.2% under the optimum reaction conditions. The catalyst being of high catalytic activity for the esterification reactions was prepared very easily and could be used repeatedly.     

固体酸SO2-4/ZrO2-MoO3催化合成富马酸二甲酯

在固体酸SO2-4/ZrO2-MoO3催化下,由马来酸酐和甲醇催化合成了富马酸二甲酯.探讨了催化剂用量,原料配比,反应时间对产率的影响.最佳反应条件为醇酸摩尔比为61,反应时间3 h,催化剂占反应物总质量的1.5%,产物收率在93%以上.     

固体酸催化剂SO2-4/SiO2-TiO2的制备及其催化酯化性能

 分别以机械混合法和浸渍法制备了SO2-4/SiO2-TiO2固体酸催化剂,以乙醇和乙酸的酯化反应为模型反应考察了不同SiO2含量及不同温度焙烧的催化剂的活性. 结果表明,机械混合法制备的400 ℃焙烧的SO2-4/40%SiO2-TiO2催化剂活性最高,部分回流时,乙酸几乎全部转化,全回流反应100 min时,其乙酸转化率达到84%. X射线衍射分析表明, SiO2抑制了硫酸氧钛的形成; 催化剂的活性组分包括一定量的四方晶锐钛矿型TiO2、 正交晶硫酸氧钛、少量立方晶金属钛和高比表面积的SiO2. 红外光谱分析表明,添加SiO2后催化剂形成 Ti-O-Si 键,进而使SO2-4与样品表面产生强相互作用; 结合的SO2-4主要以无机螯合状双配位和有机硫酸酯两种结构形式存在. 热重-示差扫描量热分析表明, SiO2的添加使SO2-4不易脱除,同时使锐钛矿TiO2向金红石相的转变温度降低.     

固体超强酸催化剂SO2-4/TiO2-WO3的制备及其催化性能研究

制备了固体超强酸催化剂SO2-4/TiO2-WO3,并以丁酸丁酯的合成作为探针反应,系统考察了WO3的含量、硫酸浸渍浓度、焙烧温度等制备条件对SO2-4/TiO2-WO3催化活性的影响.实验表明:制备催化剂的适宜条件为m(H2WO4)=12.5%,硫酸浸渍浓度为1.0 mol·L-1,焙烧温度为580℃,活化时间3 h.利用优化条件下制备的催化剂SO2-4/TiO2-WO3催化合成缩醛(酮),在醛/酮与二元醇(乙二醇,1,2-丙二醇)的投料摩尔比为1:1.5,催化剂的用量占反应物总投料质量的0.5%,反应时间为l h条件下,2-甲基-2-乙氧羰甲基-1,3-二氧环戊烷的收率为78.7%,2,4-二甲基-2-乙氧羰甲基-1,3-二氧环戊烷的收率为83.0%,环己酮-乙二醇缩酮的收率为85.9%,环己酮-1,2-丙二醇缩酮的收率为84.6%,丁酮-乙二醇缩酮的收率为70.7%,丁酮-1,2-丙二醇缩酮的收率为88.3%,2-丙基-1,3-二氧环戊烷的收率为80.6%,4-甲基-2-丙基-1,3-二氧环戊烷的收率为79.6%,2-异丙基-1,3-二氧环戊烷的收率为64.2%,4-甲基-2-异丙基-1,3-二氧环戊烷的收率为83.3%,2-苯基-l,3-二氧环戊烷的收率为75.3%,4-甲基-2-苯基-1,3-二氧环戊烷的收率为95.1%.     

对甲苯磺酸催化合成乳酸异戊酯

报道了对甲苯磺酸在异戊醇和乳酸酯化反应中的应用 ,讨论了合成条件。实验表明其催化活性良好。     

Preparation and Catalytic Activity of SO42-/TiO-La2O3 in Synthesis of Butyl Butyrate

Butyl butyrate is a very important compound, which is transparent liquid and has the pear,apple flavor. Natural exist is in the fruit, such as apple, pear, banana, grape and strawberry, etc.Primarily used for to prepare the edible spice and is also widely used in industrial intermediate product, solvent and synthetic perfumery. Until now, there are many methods to synthesize it.Conventionally H2SO4 was reported, but it causes many problems, such as the erosion of equipment,easily causes the vice-reaction, difficulty for after-treatment, environment pollution etc. A new environmentally friendly catalyst, SO42-/TiO2-La2O3 was prepared. And catalytic activity of catalyst in esterification of n-butanoic acid and n-butyl alcohol with SO42-/TiO2-La2O3 as catalyst has been no report up to now. Therefore, studying on the synthetic catalyst has theoretical and practical significances. The catalytic activity of catalyst in esterification of n-butanoic acid and n-butyl alcohol was measured.In this paper, we fast reported the preparation of SO42-/riO2-La2O3 and discussed the factors influencing the synthesis catalyst. The catalyst rare earth solid superacid SO42-/TiO2-La2O3 was The precipitate was filtered and washed thoroughly with distilled water until chloride ions were free.furnace at 480 ℃ for 3 h, and finally stored in a desiccator until use.The factors influencing the synthesis were discussed and the best conditions were found out. The experiment indicated that this catalyst has the following advantage. The amount of catalyst was little and getting high yield, its product has a good quanlity and is favour of reducing erosion of equipment, avoiding environment pollution. The optimum conditions are: molar ratio of n-butanoic acid to n-butyl alcohol was 1:1.5, the quantity of catalyst was equal to 1.5% of feed stocks, the reaction temperature was 93-114 ℃, and the reaction time was 1.0 h. Rare earth solid superacid SO42-/TiO2-La2O3 is an excellent catalyst for synthetizing butyl butyrate and its yield can reach over 90.0%.A good catalyst should be able to be used repeatedly. The reusing of the catalyst was studied. We found that the catalytic activities of our catalyst are almost unchanged after it had been used five times. From the above results and discussion, we can see that the synthesis of n-butyl butyrate by SO42-/TiO2-La2O3 instead of H2SO4 has a great prospect of application. It has a good applied foreground.     

SO_4~(2-)/SnO_2/SBA-15固体酸催化剂的制备及其在环酮缩合反应中的应用

采用等体积浸渍法制备了不同负载量的固体酸催化剂SO42-/SnO2/SBA-15,利用X射线粉末衍射、N2吸附-脱附和透射电镜等手段对样品进行了表征,并考察了催化剂对4-叔丁基环己酮与乙二醇缩合反应的催化性能.结果表明,SO42-/SnO2催化剂负载于SBA-15后其催化性能明显改善.研究了SO42-/20%SnO2/SBA-15催化剂上部分酮类化合物与乙二醇及1,2-丙二醇的缩合反应,并考察了反应时间和催化剂用量等因素对反应性能的影响.在适宜的温和条件下,一些环酮类底物如环己酮、4-甲基环己酮和4-叔丁基环己酮等均可反应得到相应的缩醛化产物,且催化剂至少可循环使用4次.     

固体酸催化剂SO4^2-／SiO2-TiO2的制备及其催化酯化性能

分别以机械混合法和浸渍法制备了SO42-/SiO2-TiO2固体酸催化剂,以乙醇和乙酸的酯化反应为模型反应考察了不同SiO2含量及不同温度焙烧的催化剂的活性.结果表明,机械混合法制备的400℃焙烧的SO42-/40%SiO2-TiO2催化剂活性最高,部分回流时,乙酸几乎全部转化,全回流反应100min时,其乙酸转化率达到84%.X射线衍射分析表明,SiO2抑制了硫酸氧钛的形成;催化剂的活性组分包括一定量的四方晶锐钛矿型TiO2、正交晶硫酸氧钛、少量立方晶金属钛和高比表面积的SiO2.红外光谱分析表明,添加SiO2后催化剂形成Ti-O-Si键,进而使SO42-与样品表面产生强相互作用;结合的SO42-主要以无机螯合状双配位和有机硫酸酯两种结构形式存在.热重-示差扫描量热分析表明,SiO2的添加使SO42-不易脱除,同时使锐钛矿TiO2向金红石相的转变温度降低.     

固体超强酸SO /SiO2-TiO2催化合成异维生素C钠

在异维生素C钠（D-VcNa）的合成过程中,以SO4^2-/SiO2-TiO2复合固体超强酸作为酯化反应催化剂,2-酮基-D-葡萄糖酸（2-KGA）和甲醇为原料,采用精馏脱水酯化工艺,不断除去酯化过程中产生的水.催化剂的最佳焙烧温度为550℃,催化剂用量为2.5%;反应时间3～4 h,产品收率为88.6%,催化剂的重复使用性较好,催化体系优于硫酸法.     

十二水合硫酸铁铵催化合成丁酸异戊酯

以十二水合硫酸铁铵为催化剂,由丁酸和异戊酸合成了丁酸异戊醋,优化了酯化条件。实验结果表明,催化剂的催化活性高,反应条件温和,易于操作,方法简便,酯化率可达９６．５％。