抗水性固体酸SO_4^(2-)-TiO_2-Clay催化剂的制备及应用

Preparation and Catalytic Performance of Hydrophobic SO_4^(2-)-TiO_2-Clay Solid Acid Catalyst

固体酸催化剂以其对设备无腐蚀，后处理工艺简单，选择性好和催化剂易回收等优势逐步替代液体酸，日益受到人们的重视，特别是抗水性固体酸催化剂，因其有高活性和可回收循环使用的特点．受到了广泛的关注。

A new solid acid of SO4^2--TiO2-Clay was supported on activated clay, and was applied to the esterification reaction of fatty acid with methanol. The influence of preparation conditions of the supported SO4^2--TiO2-Clay on the catalytic performance was studied using the above esterification reaction in a tank reactor. The supported SO4^2--TiO2 exhibited high catalytic activity and stability. The optimized conditions were as follows： reaction temperature 70 ℃, mmethanol：mfatty acid=0.43：1, catalyst amount of 5% on weight basis of fatty acid, and reaction time of 8 h. The catalytic activity was almost unchanged after twenty reaction recycles. The catalysts were also characterized by XRD, SEM, TGA/DSC, low temperature nitrogen adsorption-desorption and in situ FTIR. The results indicate that SO4^2--TiO2 is finely dispersed on the activated clay and the acidic center is typical of L-acid. These show that the activated clay as support of SO4^2--TiO2 is an efficient hydrophobic solid acid material.