化学学报 ›› 2006, Vol. 64 ›› Issue (21): 2165-2168. 上一篇    下一篇

研究论文

多金属氧酸盐/介孔分子筛杂化材料的制备与表征

张蓉芳, 杨春*   

  1. (南京师范大学化学与环境科学学院 南京210097)
  • 投稿日期:2006-01-12 修回日期:2006-06-22 发布日期:2006-11-14
  • 通讯作者: 杨春

Preparation and Characterization of Hybrid Polyoxometalate-mesoporous Molecular Sieve Materials

ZHANG Rong-Fang; YANG Chun*   

  1. (School of Chemistry and Environment Science, Nanjing Normal University, Nanjing 210097)
  • Received:2006-01-12 Revised:2006-06-22 Published:2006-11-14
  • Contact: YANG Chun

采用嵌段共聚物模板P123和缺位Keggin结构的多金属氧酸盐K8SiW11O39•12H2O, 由溶胶-凝胶法合成了具有类六方结构的SiW11/SBA-15杂化介孔分子筛材料, 并通过X射线衍射(XRD)、傅立叶变换红外光谱(FT-IR)、紫外漫反射光谱(UV/DRS)、电感耦合等离子原子发射光谱(ICP-AES)、低温N2吸附、透射电子显微镜(TEM)等手段对其进行了表征. 结果表明, 杂化材料中不仅规整均一的类六方介孔结构得以保持, 而且多金属氧酸盐的Keggin单元保留完整(含量达25%左右), 并共价键联于介孔材料的孔道内部. 稳定性实验表明, 杂化材料中多金属氧酸盐在水中的流失率远低于一般浸渍法制备的样品.

关键词: 多金属氧酸盐, 缺位Keggin阴离子, SBA-15, 介孔分子筛

Hybrid mesoporous molecular sieve material based on lacunary polyoxometalate, K8SiW11O39•12H2O, was prepared via sol-gel method as well as block copolymer templating technique. The as-obtained SiW11/SBA-15 composites were characterized by FT-IR, UV/DRS, XRD, ICP-AES, N2 adsorption-desorption and TEM. The results indicate that not only a hexagonal-like packing of channels with homogeneous pore diameter is maintained in the hybrid materials, but also Keggin units remain perfectly with a content of ~25% and are grafted onto the pore wall of mesoporous silica by covalent linkage. The immobilization degree of polyoxometalate was measured in water at 25 ℃ and compared with those of the samples prepared by impregnation. It is shown that the lost percent of polyoxometalate in the hybrid material is much less than those of the impregnated samples.

Key words: polyoxometalate, lacunary Keggin anion, SBA-15, mesoporous molecular sieve