多孔二氧化钛负载型硅钨杂多酸的制备与表征

Synthesis and characterization of silicon tungsten heteropoly acid loaded on porous titania

为了使硅钨酸催化剂在使用后能分离出来并重复使用,以硫酸钛为钛源,十六烷基三甲基溴化铵为模板剂,在酸性条件下,分别采用浸渍法和溶胶-凝胶法合成2种负载型的硅钨酸/多孔二氧化钛.采用IR、TGA-DSC和N2-吸附脱附等方法对催化剂的结构和性质进行表征,并以乙酸异戊酯的合成作为评价反应,考察所制备的硅钨酸/多孔二氧化钛催化剂的催化活性和重复使用性.结果发现:采用溶胶-凝胶法所制备的硅钨酸/多孔二氧化钛(Ⅱ)中,硅钨酸和载体二氧化钛的结合更加牢固,对乙酸异戊酯的合成反应具有很好的催化活性和重复使用性.

In order to improve the reusability of H4SiW12O40/TiO2 , two kinds of H,SiWnO40/TiO2 were synthesized by impregnation method and sol-gel synthesis method in acidic condition separately with titanium sulfate as titanium and hexadecyl trimethyl ammonium bromide as template. Their structures and properties were characterized by IR, TGA-DSC and N2 adsorption-desorption method. Isoamyl acetate synthesis reaction was adopted to evaluate the catalytic activity and reusability of H4SiW12O40/TiO2. The results showed that H4SiW12O40/TiO2 （sol-gel） synthesized by sol-gel method had better catalytic activity and reusability in synthesis of isoamyl acetate,