Dehydration, hydrolysis and oxidation of cerium chloride heptahydrate in air atmosphere

Abstract

The thermal decomposition of CeCl3·7H2O was studied from room temperature to 800 °C. Analysis was performed by applying TG–DTA, XRD, FESEM, EDXS, and TG–MS technologies to investigate the thermal decomposition mechanism of CeCl3·7H2O in air atmosphere. Multiple forms of hydrated cerium chloride compound were observed in the dehydration products. The CeCl3 hydrolysis product was separated by a continuous centrifugation method and the phase composition was identified as CeO2, Ce(OH)3, and CeCl3·4H2O by XRD analysis. The evolved gas composition was identified as Cl2 and HCl by TG–MS system. Based on the analysis of the experimental results, the mechanism of thermal decomposition of CeCl3·7H2O was proposed with completion of the dehydration reaction at 224 °C, the hydrolysis reaction at 170–480 °C, and the oxidation reaction of CeCl3 above 480 °C.