Studies On The Preparation Of Supported Phosphotungstic Acid And The Synthesis Of Dibasic Ester In The Catalysis

This article takes 12-phosphotungstic acid and esterification reaction as the main research content. On the basis of the research about the preparation of 12-phosphotungstic acid, we studied the effect of different supported methods and different carriers to the supported capacity of phosphotungstic acid and catalytic activity, then tried to find the most suitable supported catalyst in the esterification reaction by Dibasic acids and methanol, and optimized the preparation procedures. We studied the impact of response parameters, optimized the operation, improved the conversion rate and the productivity of Mixture of binary acids and mixed Dibasic ester. Then, on the basis of small-scale experiment, we designed the amplification tests experiment, studied the preparation of mixed dibasic acid, its supported capacity and the possibility of scale-up experiment.Firstly two different methods directly and indirectly are adopted to prepare 1-2 phosphotungstic acid, then optimized the operating parameters. The productive rate is 89.20% 94.12% respectively; it is found that the amount used of acid and ether of the latter method is less than that of the former.so that the indirect synthetic method is better. The characterization by IR,XRD,TG-DSC and Hammett indicator showed same feature of the product by the two methods, , splendid grain size, preferable thermal stability, strong acidity and analysis activity, with six crystal water, the conversation rate reached 94.9%.Taking supported capacity and analysis activity as evaluation criterion, different procedures are used to prepare the catalysis, optimized the preparation conditions, the supported capacity and conversation rate are as following: mutiple impregnation by organic solvent to prepare H₃PW₁₂O₄₀/C: 2.645g, return flow. 2.9672g and citric acid sol-gel method to prepare H₃PW₁₂O₄₀/SiO₂: 2.6229g, the conversation rate is 94.8%, 95.0% and 94.8%. Then they were characterized by different methods of IR,XRD,TG-DSC and Hammett indicator, the result indicated that the H₃PW₁₂O₄₀ preserved its Keggin construction on the two different carriers, and had good dispersibility and high acidity, at the same time the thermal stability is...