TY - JOUR
T1 - Characterization of iron oxide in Fe2O3 SiO2 catalyst
AU - Ida, Takashi
AU - Tsuiki, Hideyasu
AU - Ueno, Akifumi
AU - Tohji, Kazuyuki
AU - Udagawa, Yasuo
AU - Iwai, Kumiko
AU - Sano, Hirotoshi
PY - 1987/8
Y1 - 1987/8
N2 - Silica-supported iron oxide catalyst was prepared by hydrolysis of a mixed solution of ethyl silicate and iron(III) nitrate dissolved in ethylene glycol. A gel obtained by the hydrolysis was dried and calcined at various temperatures. The iron oxide particles thus prepared were maghemite (γ-Fe2O3), deduced by EXAFS (extended X-ray absorption fine structure) measurements and the sample color. The maghemite particles were classified into two groups: one is small but detectable by transmission electron microscopy (TEM) and the other is too small to be detected by TEM. The former was well controlled to a consistent size, which depended on the calcination temperature, and exhibited ferrimagnetic properties. The latter showed superparamagnetic properties and was estimated to be smaller than 10 Å in particle size by magnetic and Mössbauer measurements at low temperature. For comparison, the catalyst was also prepared by a conventional impregnation method using silica powder and an aqueous solution of iron(III) nitrate. Iron oxide thus prepared was hematite (α-Fe2O3) and the particle sizes were broadly distributed.
AB - Silica-supported iron oxide catalyst was prepared by hydrolysis of a mixed solution of ethyl silicate and iron(III) nitrate dissolved in ethylene glycol. A gel obtained by the hydrolysis was dried and calcined at various temperatures. The iron oxide particles thus prepared were maghemite (γ-Fe2O3), deduced by EXAFS (extended X-ray absorption fine structure) measurements and the sample color. The maghemite particles were classified into two groups: one is small but detectable by transmission electron microscopy (TEM) and the other is too small to be detected by TEM. The former was well controlled to a consistent size, which depended on the calcination temperature, and exhibited ferrimagnetic properties. The latter showed superparamagnetic properties and was estimated to be smaller than 10 Å in particle size by magnetic and Mössbauer measurements at low temperature. For comparison, the catalyst was also prepared by a conventional impregnation method using silica powder and an aqueous solution of iron(III) nitrate. Iron oxide thus prepared was hematite (α-Fe2O3) and the particle sizes were broadly distributed.
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U2 - 10.1016/0021-9517(87)90255-7
DO - 10.1016/0021-9517(87)90255-7
M3 - Article
AN - SCOPUS:0000585918
VL - 106
SP - 428
EP - 439
JO - Journal of Catalysis
JF - Journal of Catalysis
SN - 0021-9517
IS - 2
ER -