Hydrothermal preparation and characterization of boehmites

被引：129

作者：

Mishra, D ^{[1
]}

Anand, S ^{[1
]}

Panda, RK ^{[1
]}

Das, RP ^{[1
]}

机构：

[1] Reg Res Lab, Bhubaneswar 751013, Orissa, India

来源：

MATERIALS LETTERS | 2000年 / 42卷 / 1-2期

关键词：

hydrothermal; boehmite; gel-dehydration; gamma-alumina;

D O I：

10.1016/S0167-577X(99)00156-1

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Boehmites (Al2O3 . xH(2)O, 1 < x < 1.5) have been prepared hydrothermally from Al(NO3)(3) . 9H(2)O and urea. Effect of temperature on preparation was studied in the range of 160 degrees-220 degrees C. No precipitation of boehmite was observed until the attainment of similar to 160 degrees C at which temperature a partly amorphous gel started precipitating. With the increase in temperature, transformation of the amorphous precipitate into crystalline boehmites took place as indicated by the X-ray diffraction (XRD) patterns. From the weight loss studies of the samples prepared at different temperatures and for different reaction time intervals, the value of x was estimated to vary between 1.3 and 1.5. The Fourier transform infrared (FTIR) spectra of samples obtained at 180 degrees, 200 degrees or 220 degrees C showed 25-40 cm(-1) upward shift in the -OH stretching and bending vibrations assigned to boehmites. gamma-Alumina obtained by subsequent calcination of boehmite at 725 degrees C was also characterized by XRD. (C) 2000 Elsevier Science B.V. All rights reserved.

引用

页码：38 / 45

页数：8