Al_2(SO_4)_3-NH_3·H_2O法大孔拟薄水铝石的制备及其应用

在Al3+浓度0.6 mol·L-1、反应温度60℃和p H=9条件下,研究了硫酸铝滴定氨水(酸滴碱法)、氨水滴定硫酸铝(碱滴酸法)、p H摆动法和并流法成胶方式对共沉淀法制得的拟薄水铝石物化性能的影响。采用X射线衍射、N2吸附-脱附和扫描电镜等对拟薄水铝石进行表征。结果表明,成胶方式对拟薄水铝石物理性能影响显著,采用并流法成胶方式制得的拟薄水铝石比表面积374 m2·g-1,孔容0.89 cm3·g-1,孔径6.4 nm且分布集中,结晶度高,纯度好,能够满足加氢催化剂载体所用拟薄水铝石的物化性能要求。以并流法成胶方式得到的拟薄水铝石制备的Pd/Al2O3催化剂用于裂解汽油双烯烃选择加氢时表现出优异的加氢性能。

Preparation of macropore pseudo-poehmite by Al2(SO4)3-NH3 ·H2 O process and its application

Pseudo-boehmite was prepared by Al₂(SO₄)₃-NH₃·H₂O process.Under the condition of Al3+ concentration 0.6 mol·L^-1,reaction temperature 60 ℃ and pH=9,the influence of precipitation methods on the physicochemical properties of pseudo-boehmite was investigated by X-ray diffraction,nitrogen adsorption-desorption and scanning electron microscope.The results showed that the precipitation methods had great influence on product properties.The pseudo-boehmite obtained by the parallel flow method possessed specific surface area of 374 m²·g^-1,pore volume of 0.89 cm³·g^-1,pore diameter of 6.4 nm with intensive distribution,high crystallinity and good purity,which could meet the requirement of physical properties of pseudo-boehmite for the preparation of hydrogenation catalyst supports.The supported Pd/Al₂O₃ catalyst prepared from pseudo-boehmite obtained by the parallel flow method exhibited excellent hydrogenation performance in dialkenes selective hydrogenation reaction of pyrolysis gasoline.