H6P2Mo9W9O62/SiO2催化合成乙酸异戊酯

H6P2Mo9W9O62/SiO2催化合成乙酸异戊酯(论文9200字)
摘  要
酯类物质一般指的是一种有机物，通常是由酸类物质与醇类物质的羟基与羧基在催化剂的作用下发生脱水缩合的反应生成。酯化反应一般是可逆的，而且一般反应速率与产率很慢很低，故需要催化剂对反应进行催化，一般用浓硫酸做催化剂。而用硫酸做催化剂有许多如硫酸会对环境造成影响和有较强的腐蚀性等缺点，所以需要寻找更加适合的催化剂。H6P2Mo9W9O62/SiO2就是一个好的选择
用钼酸钠与钨酸钠在浓磷酸中制备H6P2Mo9W9O62。再用硅酸钠制得硅胶与磷钨酸混合，制得H6P2Mo9W9O62/SiO2。在将制得的催化剂与乙酸和异戊醇混合，加热，温度控制在135℃左右，冷凝回流，反应1.5h制得乙酸异戊酯粗产物，洗涤干燥后再进行蒸馏操作收集138~145℃的产物，得到最终产物乙酸异戊酯。并通过改变催化剂的各种条件测得使用该催化剂能很好的缩短反应时间，催化的活性提高，并且能很好的提高产率与生产效率，并且能简化工艺流程。经过实验，该催化剂还能重复利用于特定情况下。从反应结果上来看，该反应的最佳条件为1.5h的反应时间，催化剂用量为1.0g，乙酸与异戊醇的物质的量比例为1.0:1.5。该催化剂的重复使用次数为5次，在5次重复使用中，催化剂的催化活性，催化效果没有受到太大影响。实验可以增加带水剂来使产率提高。
关键词：二氧化硅 乙酸异戊酯 催化合成 H6P2Mo9W9O62/SiO2

Catalytic Synthesis of Isoamyl Acetate by H6P2Mo9W9O62/SiO2
Abstract
An ester substance generally refers to an organic substance, which is usually produced by a reaction in which a hydroxyl group and a carboxyl group of an acid substance and an alcohol substance are dehydrated and condensed by a catalyst. The esterification reaction is generally reversible, and generally the reaction rate and the yield are very slow and low, so that the catalyst is required to catalyze the reaction, and concentrated sulfuric acid is generally used as a catalyst. The use of sulfuric acid as a catalyst has many disadvantages such as sulfuric acid affecting the environment and having strong corrosiveness, so it is necessary to find a more suitable catalyst. H6P2Mo9W9O62/SiO2 is a good choice
H6P2Mo9W9O62 was prepared by using sodium molybdate and sodium tungstate in concentrated phosphoric acid. The silica gel is then mixed with phosphotungstic acid by using sodium silicate to obtain H6P2Mo9W9O62/SiO2. The prepared catalyst is mixed with acetic acid and isoamyl alcohol, heated, the temperature is controlled at about 135℃, condensed and refluxed, and reacted for 1.5 hours to obtain a crude product of isoamyl acetate. After washing and drying, distillation is carried out to collect 138~145℃. The product gave the final product isoamyl acetate. By changing various conditions of the catalyst, it is found that the use of the catalyst can shorten the reaction time, improve the catalytic activity, and can improve the yield and production efficiency, and can simplify the process. After experimentation, the catalyst can also be reused in specific situations. From the viewpoint of the reaction results, the optimum conditions for the reaction were a reaction time of 1.5 h, a catalyst amount of 1.0 g, and a ratio of the amount of acetic acid to isoamyl alcohol of 1.0:1.5. The number of times of repeated use of the catalyst was 5 times, and the catalytic activity of the catalyst and the catalytic effect were not greatly affected in 5 times repeated uses. Experiments can increase the water-carrying agent to increase the yield.
Key Words: Silica; isoamyl acetate;catalytic synthesis;H6P2Mo9W9O62/SiO2
 

目  录
摘要    II
ABSTRACT    III
目  录    IV
第一章 前 言    1
1.1 酯类物质以及乙酸异戊酯    1
1.2 酯化反应的新催化剂与研究方向    2
1.3 杂多酸催化剂的研究与进展    3
1.4 磷钨酸    4
1.5 载体二氧化硅    4
1.6 带水剂    5
第二章 实验部分    6
2.1 实验仪器与试剂    6
2.2 催化剂的制备     6
2.3乙酸异戊酯的合成    6
2.4实验的结果与讨论    7
第三章 结语    11
参考文献    12
致  谢    13