纳米孔结构负载型固体杂多酸催化合成乙酸乙酯的研究

Study on Catalyzing and Synthesizing Ethyl Acetate under Nanosize and porous Solid Supported Heteropoly Acid Catalysts

采用溶胶-凝胶技术分别将Keggin型和Dawson型杂多酸负载到TiO2载体上,制备了固体杂多酸催化剂H3PW12O40/TiO2、H4SiW12O40/TiO2和H6P2W18O62/TiO2,通过ICP-AES、31P MAS NMR和N2吸附测定方法对其进行了表征,并对催化剂在合成乙酸乙酯反应中的催化性能进行了对比研究。实验结果表明,负载型杂多酸在反应中的活性高于母体杂多酸的直接催化。其中,H6P2W18O62/TiO2可在120min内使乙酸乙酯收率达到98%。

The composites of supported heteropoly acids H3PW12O40/TiO2,H4SiW12O40/TiO2 and H6P2W18O62/TiO2 were prepared by the method of sol-gel. All of these materials were characterized by ICP-AES, 31^P MAS NMR and N2 adsorption. The results indicated that the primary Keggin or Dawson structure remained intact and chemical interactions in the composites. As-synthesized materials were studied by catalyzing and synthesizing ethyl acetate. The results showed that the catalytic activities of the supported catalysts were higher than that of the pure. heteropoly acids. Yield of ethyl acetate can reach 98% within 120 minutes with H6P2W18O62/TiO2 as catalyst.