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Characterization of Alumina Doped with Lanthanum and Pluronic P123 via Sol-Gel Process

고분자 P123와 란탄이 도핑된 알루미나의 특성 연구

  • Jung, Mie-Won (Department of Chemistry, Sungshin Women's University) ;
  • Lee, Mi-Hoe (Department of Chemistry, Sungshin Women's University)
  • Published : 2008.05.31

Abstract

To direct the evolution of nanostructure and immobilize ${\gamma}-Al_2O_3$ catalyst, nanocrystalline La-doped-$Al_2O_3$ powder were prepared by the sol-gel process with addition of an amphiphilic block copolymer template (pluronic P123: $(poly(ethyleneoxide)_{20}-poly(propyleneoxide)_{70}-poly(ethyleneoxide)_{20})$. The dried gel is amorphous, whereas heating at temperature above $700^{\circ}C$ leads to the formation of nanocrystalline ${\gamma}$ and ${\delta}-Al_2O_3$ and these two phases is kept until $1100^{\circ}C$. ${\alpha}-A1_2O_3 $starts to form at $1200^{\circ}C$ with $LaAl_{11}O_{18}$. The surface morphology and crystal structure has been observed by field emission scanning electron microscope (FE-SEM) and X-ray diffraction (XRD). Solid state $^{27}Al$ MAS NMR indicates two types of local environment, i.e. octahedral and tetrahedral sites. The surface area and pore size was compared among these powders using the BET nitrogen adsorption measurements.

Keywords

References

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