Synthesis of tributyl citrate by heteropoly acids supported on SBA-15 prepared by impregnation method

Heteropoly acids supported on SBA-15 by impregnation method was used as catalysts of tributyl citrate. The parameters affecting on the esterification ratio were investigated, such as the ratio of alcohol to acid, temperature, the amount of catalyst and reaction time. The experiments indicate that the activity of heteropoly acids supported on SBA-15 is high. The proper reaction conditions are followings:mol ratio of alcohol to acid is 4∶1, the capacity of heteropoly acid is 27%, the percent of catalyst in reactants is 1.3%, reaction time is 7 h, and the esterification ratio can reach to 96%.