固体超强酸SO_4^(2-)/ZrO_2的制备及其催化性能研究

Preparation and Catalytic Performance Research of SO_4^(2-)/ZrO_2 Solid Superacid Catalyst

以氧氯化锆为锆原,氨水为沉淀剂,硫酸溶液为浸渍液,通过沉淀-浸渍法制备SO_4^(2-)/ZrO_2(SZ)酯化催化剂,其结构经BET、X-射线衍射(XRD)、傅立叶变换红外光谱(FT-IR)及扫描电子显微镜(SEM)表征。结果表明:随着焙烧温度升高,催化剂的比表面积依次降低,孔径增大,氧化锆的晶态由无定形态转化为四方晶态再转化为单斜晶态;于600℃焙烧时,催化剂形成的S=O键红外吸收峰最强;于700℃焙烧时,催化剂结构被破坏。在丙烯酸与十八醇的酯化反应中对催化剂进行活性测试。结果表明:600℃焙烧的催化剂产率最高(96.4%)。

The SO2-/ZrO2 （SZ） esterification catalysts were prepared by precipitation-impregnation method using zirconium oxychloride as zirconium, ammonia as precipitant and sulfuric acid solution as impregnation solution. The structures were characterized by BET, X-ray diffraction （XRD）, Fourier transform infrared spectroscopy（FT-IR） and scanning electron microscopy（SEM）. The results showed that the specific surface area of the catalyst decreased, and the pore size of the zirconia changed from amorphous to tetragonal and then converted into monoclinic with increasing of the calcination tempera- ture. The catalysts calcined at 600 ℃ formed the strongest S = O bond infrared absorption peak. The solid super acid structure could be seriously damaged when calcined at 700 ℃. The catalytic perform- ance in the esterification reaction of acrylic acid with stearyl alcohol were investigated . The results showed that the yield was 96.4% for the catalyst calcined at 600 ℃.