SO_4^(2-)/TiO_2-ZrO_2-Nd_2O_3催化剂的制备及其催化合成双季戊四醇六脂肪酸酯

Preparation of SO_4^(2-)/TiO_2-ZrO_2-Nd_2O_3 solid superacid and its catalytic activities in esterification of dipentaerythritol hexa-esters

用共沉淀和浸渍法制备SO24-/TiO2-ZrO2-Nd2O3三元超强酸,以其为催化剂,合成双季戊四醇六辛酸酯,考察了钕(Nd)的质量分数、焙烧时间、焙烧温度对三元超强酸催化性能的影响;同时采用正交试验对制备条件进行了优化。催化剂用BET、SEM、XRD、FTIR表征,双季戊四醇六辛酸酯的结构采用FTIR表征。结果表明,加入Nd使固体酸体积变大,酸性增强,550℃时超强酸中的TiO2由无定型结构变为锐钛矿晶型结构,SO24-/TiO2-ZrO2-Nd2O3的最佳制备条件是Nd质量分数为1.5%,焙烧温度550℃,焙烧时间4h,其酯化率达92.3%。FTIR表征结果认证了产品为双季戊四醇六辛酸酯。

Solid superacid SO4z /TiO2-ZrO2-Nd203 was prepared by impregnation-deposition method and characterized by BET, SEM, XRD and FTIR. The effect of preparation conditions including content of Nd, calcining time and temperature on the catalytic activity were investigated. The particle size of superacid grew and swelled after introducing of Nd and the acidity was strengthened. The structure of TiO2 was turned to rutile anatase from amorphous. The optimum preparation condition are described as follows. Nd content 1.5%, calcining temperature 550 ℃, calcining time 4 h, and in this condition, the yield of ester is 92.3%. FTIR analysis indicated that the synthesized ester is dipentaerythritol hexa-esters.