Thermal decomposition of potassium perchlorate in presence of chromium(III) oxide and nickel(II) chromite(III)

Abstract

A study of the thermal decomposition of intimate mixtures of different molar ratios of potassium perchlorate and chromium(III) oxide, and potassium perchlorate and nickel(II) chromite(III) was conducted employing thermogravimetry, differential thermal analysis, chemical analysis, infrared spectroscopy and X-ray diffraction analysis. Upon heating to 400°C Cr(III), in 2:1 molar ratios, is oxidized to potassium dichromate. Only a stoichiometric amount of Cr(III) was oxidized from molar ratios less than 2:1, leaving behind excess Cr 2O 3 and NiCr 2O 4 whereas from molar ratios greater than 2:1, Cr(III) was completely oxidized and the excess KClO 4 started decomposing around 410°C which is much below the decomposition temperature of pure KClO 4.