Synthesis of n-butyl p-hydroxybenzoate catalyzed by nanometer rare earth composite solid superacid SO42-/ZrO2-2% Nd2O3

Rare earth composite solid superacid SO2- 4 /ZrO 2-2% Nd 2 O 3 was prepared by coprecipitation method. The measure result of TEM indicated that catalyst particle was nanoparticle. It was used as catalyst in the esterification reaction between p-hydroxy-benzoic acid and n-butanol.The main influential factors of reaction were investigated.The results showed that the optimum reaction conditions for preparing n- butyl p- hydroxybenzoate were as follows: Excess of n- butanol acted as azeotropic water stripping agents, reaction time by refluxing was 3.0h, the mass ratio of catalyst to p- hydroxy- benzoic acid was 3.5%, and the molar ratio of n- butanol and p-hydroxy benzoic acid was 3.0∶1.0.Under these condition, the yield of the product reached 97.5%.Meanwhile, the products were characterized by melting point determination, elemental analysis, HPLC and IR spectrum.The results demonstrated that as- synthesized products were n- butyl p- hydroxybenzoate with high purity. Furthermore, the self-synthetical catalyst exhibited high catalytic activity, could be recycled and used for many times.