Synthesis of Tributyl Citrate Catalyzed by Phosphotungstic Acid Supported on Activated Carbon

A supported catalyst phos photungstic acid was prepared and investigated for the esterificated of n-butanol with citric acid in the liquid-solid system. The effects of the quantity of；catalyst, ratio of the reactants and reaction time were examined. The percentage of the esterification can reach to 91.7% under the most suitable conditions as follows:solid quantity 34%, citric acid to n-butand acidl: 4(mol), mass of catalyst 2.5g, reaction time 2.5 h and reaction temperature 140℃. The experimental result showed that the supported phosphotungstic acid catalyst had high activity and stability.