钛-硅复合氧化物比表面积的影响因素研究

以无机盐为原料采用溶胶-凝胶法制备了钛-硅复合氧化物（TiO₂-SiO₂）。利用氮气吸附-脱附法对复合氧化物进行了比表面积分析。考察了原料配比、加料方式、表面活性剂、反应温度、老化温度、老化时间、焙烧温度等因素对复合氧化物比表面积的影响。综合结果表明：当二氧化钛质量分数为22%、添加剂为十六烷基三甲基溴化铵（CTAB）、反应温度为30 ℃、老化温度为70 ℃、老化时间为1 h、焙烧温度为150 ℃时,制备的复合氧化物的比表面积为361.4 m²/g、孔容为1.18 cm³/g、平均孔径为13.0 nm。不同因素对比表面积均有一定的影响,依据规律可以实现复合氧化物比表面积的可控调变。

Study on influence factors of specific surface area of Ti-Si composite oxides

TiO₂-SiO₂ composite oxide was prepared by sol-gel method using inorganic salts.The surface area of composite oxide materials was tested and analyzed by N₂-adsorption method,and the factors,such as ratio of raw materials,feeding ways,surface active agent,reaction temperature,aging temperature,aging time and calcination temperature etc.,on the specific surface area of composite oxide were investigated.Results showed that when the mass fraction of TiO₂ was 22%,additive was CTAB,reaction temperature was 30 ℃,aging temperature was 70 ℃,aging time was 1 h and calcination temperature was 150 ℃,then the specific surface area of prepared composite oxide was 361.4 m²/g,pore volume was 1.18 cm³/g and the average pore size was 13.0 nm.Different factors all had certain influence on the surface area,the composite oxide pore structure can controlled according to rules.