Preparation of SO_4~(2-)/ZrO_2 Catalyst through Hydrothermal Modification and Its Catalytic Activity in Esterification Reaction

SO~(2-)_4/ZrO_2 solid acid catalyst was prepared from hydrothermally modified zirconium hydroxide.The liquid phase esterification of acetic acid and 1-butanol was preformed to confirm the optimal conditions of preparation.Compared experiments were made with SO~(2-)_4/ZrO_2 solid acid catalyst prepared by normal method.The catalysts were characterized with XRD and BET.The results show that the optimum preparation conditions for solid acid catalyst through hydrothermal modification are concentration of sulphuric acid 0.5 mol/L,impregnation time 120 min and calcining temperature 500 ℃.Butyl acetate are prepared by reaction at 105～110 ℃ for 2 h with n(1-butanol)∶n(acetic acid)=2∶1 and w(catalyst)=0∶27% based on the total mass of initial materials.Conversion of acetic acid amounts to 99.1%.At the optimum conditions,after the catalyst was used repeatedly four times,the catalytic activity decreased by 5%.