【作者】 韩文爱；

【导师】 郭奋；

【作者基本信息】 北京化工大学 ， 化学工程， 2004， 硕士

【摘要】 本研究课题采用乙醚萃取法制备出一系列具有Keggin结构的杂多酸，如12-钨磷酸、12-钨硅酸和12-钼磷酸。在此基础上，选择活性炭、硅胶（SiO2）、Al2O3、Y-分子筛作为载体，采用不同的负载方法，如回流吸附法、饱和浸渍法，制备出一系列的负载型杂多酸，如PW12/C、PW12/SiO2、PW12/Al2O3、PW12/Y-分子筛；并采用Hammett指示剂法、IR红外光谱法、XRD射线衍射和DTA测定对各种催化剂进行表征。本课题首次将杂多酸（钨磷酸）与对甲苯磺酸和硼酸按一定比例进行复配，用作酯化催化剂，结果表明合适的配比下的混合酸，其催化活性高于杂多酸单独使用。将自制的杂多酸和负载型杂多酸用作酯化催化剂，考察其催化活性。活性测定采用酸值法和出水速率法，从而筛选出活性好、选择性高的催化剂，用于催化合成乙酸乙酯。乙酸乙酯的合成以冰乙酸和乙醇为原料。实验分别采用间歇法和连续法进行。在间歇法中，分别考察了酸、醇摩尔比、催化剂用量、回流时间以及带水剂的种类和用量对酯化率的影响，并采用正交试验法优化出各种催化剂的最佳反应条件。同样，在连续法中，通过对反应物滴加速度、回流比、以及催化剂用量等各种因素的考察，采用正交试验法优化出最佳的实验条件。实验结果表明，12-钨磷酸、负载型杂多酸PW12/C、PW12/SiO2都是很好的酯化催化剂。在间歇反应中，收率分别可达93.78%、90.68%和91.56%；在连续反应中，收率分别可达 97.32 %、94.18%和 92.08%。催化剂回收方便，对环境无污染，<WP=4>有着广泛的应用前景。复配型杂多酸作为酯化反应的催化剂，具有很高的活性和选择性。在间歇反应和连续反应中，收率分别可达95.88%和98.36%，高于钨磷酸，降低了成本，具有很高的经济效益。更多还原

【Abstract】 A series of heteropoly acids with the Keggin structure have been prepared by ether extraction method，including 12-tungstophosphoric acid，12-molybdophosphoric acid and 12-silicotungstic acid. In addition， a series of supported heteropoly acids have also been prepared with activated carbon，silica gele，Al2O3 and Y-type zeolite as their supports by different methods such as reflux adsorption and impregnation.The catalysts were characterized by Hammeet，IR，XRD and DTA.Heteropoly acid was mixed with p-toluene sulfonic acid and oxalic acid in certain proportion for the first time. The mixed catalyst was used in the esterification.The catalytic activity was investigated by measurement of water velocity. The experimental results show that the mixed acid has better catalytic activity than heteropoly acid only. The heteropoly acid catalysts were used in the esterification. The catalytic activity of different heteropoly acids and supported heteropoly acids were investigated by measurement of acid content and water velocity. Then the catalysts of high activity and selectivity were selected to be used in the preparation of ethyl acetate.Ethyl acetate was synthesized by ethanol with acetic acid as raw <WP=6>material. The experiments were engaged in batch process and series process. In the intermittent，the molar ratio of acetate to ethanol，the content of the catalysts，the time of reaction and the content of water carrier were studied. Then the best reaction condition was determined. In addition，in the consecution method，the rate of the raw material input， the ratio of refluxing and the content of the catalyst were studied. Then the best reaction condition was also determined.It was proved that 12-tungstophosphoric acid，PW12/C and PW12/SiO2 are good catalysts to esterification. In the intermittent reaction， the yield of each catalyst was 93.78%，90.68% and 91.56% . In the consecution，the yield of each catalyst was 97.32 %，94.18% and 92.08%. And the catalysts have no corrosion and could be reused. High activity and selectivity was attained. We can foresee a bright future for the application of heteropoly acid catalyst to chemical industry.The mixed hetreopoly acid used in the esterification has high activity and selectivity. In the intermittent reaction，the yield is 95.88%. In the consecution，the yield of each catalyst was 98.36 %. It was higher than tungstophosphoric acids.更多还原