Thermal decomposition of ammonium perchlorate in the presence of Al(OH)3·Cr(OH)3 nanoparticles

Abstract

An Al(OH)3·Cr(OH)3 nanoparticle preparation procedure and its catalytic effect and mechanism on thermal decomposition of ammonium perchlorate (AP) were investigated using transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis and differential scanning calorimetry (TG-DSC), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis and mass spectroscopy (TG-MS). In the preparation procedure, TEM, SAED, and FT-IR showed that the Al(OH)3·Cr(OH)3 particles were amorphous particles with dimensions in the nanometer size regime containing a large amount of surface hydroxyl under the controllable preparation conditions. When the Al(OH)3·Cr(OH)3 nanoparticles were used as additives for the thermal decomposition of AP, the TG-DSC results showed that the addition of Al(OH)3·Cr(OH)3 nanoparticles to AP remarkably decreased the onset temperature of AP decomposition from approximately 450°C to 245°C. The FT-IR, RS and XPS results confirmed that the surface hydroxyl content of the Al(OH)3·Cr(OH)3 nanoparticles decreased from 67.94% to 63.65%, and Al(OH)3·Cr(OH)3 nanoparticles were limitedly transformed from amorphous to crystalline after used as additives for the thermal decomposition of AP. Such behavior of Al(OH)3·Cr(OH)3 nanoparticles promoted the oxidation of NH3 of AP to decompose to N2O first, as indicated by the TG-MS results, accelerating the AP thermal decomposition.