【摘要】 采用溶胶 凝胶法合成出具有Keggin结构的纳米复合杂多酸H3 PW12 O40 /SiO2 催化材料 ,用IR ,UV ,XRD ,TEM等手段研究了其结构形态 ;并考察了纳米催化剂对合成丙烯酸正丁酯的应用研究。结果表明 ,H3 PW12 O40 /SiO2 催化剂平均粒径为 4 0nm ,是一种非晶态复合物 ,H3 PW12 O40 和SiO2 之间存在着强烈的化学作用 ,纳米粒子对合成丙烯酸正丁酯有很好的催化活性 ,其最佳催化条件为 :酸醇摩尔比为 1∶1 2 ,催化剂用量为酸质量的 10 % ,反应温度为 90～ 96℃ ,反应时间 5h ,酯化率达到 94 37% ,酯收率为 91 2 %。这与纳米粒子具有较强的酸表面中心 ,高的比表面积以及“假液相”行为有关更多还原

【Abstract】 A new nanometer complex heteropoly acid with Keggin structure, H₃PW₁₂O₄₀/SiO₂, were prepared by sol-gel method, and were characterized with IR, UV, XRD and TEM techniques; By means of this nanometer catalytic materials, the optimum catalytic conditions of the n-butyl acrylate synthesis have been studied. The results show that the complex heteropoly acid H₃PW₁₂O₄₀/SiO₂ （nanoparticles） have the mean grain size of 40 nm and they are typical amorphous. A strong chemical interaction exists between (H₃PW₁₂O₄₀) and silica surface. The nanoparticles have high catalytic activity for synthesizing n-butyl acrylate. The optimum catalytic conditions are as follows: the mole ratio of acrylic acid and n-butyl alcohol is 1∶1.2, the reaction temperature is approximately 90-96 ℃, and the catalyst quantity in the reaction is 10% of the acid mass. The conversion proportion is 94.37% and product yield 91.2% in 5 h. （Apparently）, the unique structure of the Keggin anions and surface acid center and the high specific surface area and the pseudoliquid phase of H₃PW₁₂O₄₀/SiO₂ play an important role in the esterification reactions with the acid catalyst.更多还原