Aromatic as well as aliphatic esters are important classes of chemicals having a variety of applications. Valuable chemicals can be produced from 1,2-propanediol (1,2-PDO) by etherification, esterification and cyclization through acetalization. In the current study, esterification of propanoic acid was carried out with 1,2-propanediol using a clay supported heteropolyacid Cs_2.5H_0.5PW₁₂O₄₀/K-10 as solid acid catalyst in a batch reactor. The diester of 1,2-PDO was found to be formed at 180 °C. The product of this reaction, the diester of propanoic acid with propylene glycol, is approved as a safe chemical and also as a food flavoring agent in non-alcoholic beverages, chewing gums and frozen dairy products. The Cs_2.5H_0.5PW₁₂O₄₀/K-10 catalyst was prepared by the incipient wetness method, and characterization techniques such as X-ray diffraction, surface area measurement by N₂ adsorption–desorption, FTIR, and SEM were employed to study its physicochemical properties. The product was confirmed and characterised by a mass spectroscopic method. The effect of various reaction parameters such as speed of agitation, catalyst loading, mole ratio, and temperature was studied. Parameter optimization was carried out and a kinetic model developed. The apparent activation energy was found to be 13.8 kcal mol⁻¹. FT-IR and surface area analysis established that the catalyst was stable and reusable.

中文翻译：

---

1,2-丙二醇酯化丙酸：铯交换杂多酸在K-10粘土上的催化和动力学模型

芳香族和脂肪族酯是具有多种应用的重要化学类别。可以通过1,2-丙二醇（1,2-PDO）的醚化，酯化和缩醛环化来生产有价值的化学品。在当前的研究中，在分批反应器中，使用粘土负载的杂多酸Cs _2.5 H _0.5 PW ₁₂ O ₄₀ / K-10作为固体酸催化剂，用1,2-丙二醇酯化丙酸。发现1，2-PDO的二酯在180℃下形成。该反应的产物，丙酸与丙二醇的二酯，被认为是安全的化学品，并且还用作非酒精饮料，口香糖和冷冻乳制品中的食品调味剂。Cs _2.5采用初湿法制备了H _0.5 PW ₁₂ O ₄₀ / K-10催化剂，并采用X射线衍射，N ₂吸附脱附法，FTIR，SEM等表征技术研究了其理化性质。 。产物通过质谱法确认并表征。研究了各种反应参数的影响，例如搅拌速度，催化剂负载量，摩尔比和温度。进行参数优化并建立动力学模型。发现表观活化能为13.8kcal mol ^-1。FT-IR和表面积分析表明该催化剂稳定且可重复使用。