A novel hydrolysis method to synthesize chromium hydroxide nanoparticles and its catalytic effect in the thermal decomposition of ammonium perchlorate

A procedure for the preparation of spherical Cr(OH)(3) nanoparticles was developed based on the aging of chromium nitrate aqueous solutions in the presence of sodium fluoride, urea, and polyvinylpyrrolidone. Using scanning electron microscopy, transmission electron microscopy, and energy dispersive spectroscopy, the morphological characteristics of Cr(OH)(3) were controlled by altering the molar ratio of fluoride ion to chromium ion, as well as the initial pH and chromium ion concentration. The prepared nanosized Cr(OH)(3) decreased the temperature required to decompose ammonium perchlorate from 450 degrees C to about 250 degrees C as the catalyst. The possible catalytic mechanism of the thermal decomposition of ammonium perchlorate was also discussed. (C) 2012 Elsevier B.V. All rights reserved.