【摘要】 以硅藻土为载体,采用浸渍法制备了H6P2W18O62/硅藻土催化剂,并采用FTIR,EDS,XRD,SEM等手段对催化剂进行了表征;以对羟基苯甲酸正丁酯的合成反应为探针,考察了H6P2W18O62/硅藻土催化剂的性能;通过单因次和正交实验研究了H6P2W18O62负载量、催化剂用量、正丁醇与对羟基苯甲酸的摩尔比(醇酸比)、反应时间和反应温度对酯化反应的影响。确定了优化工艺条件为:H6P2W18O62负载量为40%(基于硅藻土的质量)、催化剂用量0.5 g(占反应体系总质量的2.8%)、醇酸比3、反应时间3.0 h、反应温度125℃。在此条件下,对羟基苯甲酸正丁酯的平均收率可达90.8%;催化重复使用5次,对羟基苯甲酸正丁酯收率仍可达65.6%。更多还原

【Abstract】 Diatomite supported phosphotungstic acids with Dawson structure were prepared by an impregnation method and used as catalysts for the synthesis of butyl p-hydroxybenzoate by the esterification of p-hydroxy benzoic acid with n-butyl alcohol.The effects of the catalyst preparation and reaction conditions on the esterification were investigated through orthogonal experiments.The yield of butyl p-hydroxybenzoate could reach 90.8% under the optimum conditions of phosphotungstic acid loading on the diatomite support 40%(based on the diatomite mass),mass ratio of the catalyst to the total reactants 2.8%,molar ratio of n-butyl alcohol to p-hydroxy benzoic acid 3,reaction time 3.0 h and reaction temperature 125 ℃.The catalyst could be reused for 5 times and the yield of butyl p-hydroxybenzoate was still kept at 65.6%.更多还原