Regular Article

Thermal decomposition mechanism of PrCl₃·6H₂O in air atmosphere

¹ Metallurgy school of Northeastern University, 110819 Shenyang, PR China
² School of Energy and Environmental Engineering, Inner Mongolia University of Science and Technology, 014010 Baotou, PR China

^* Corresponding author: wuwy_neu_edu@sina.com

Received: 10 April 2017
Received in final form: 27 July 2017
Accepted: 28 July 2017

Abstract

The formation of PrOCl is widely regarded as a result of PrCl₃ hydrolysis; that is, PrCl₃ + H₂O = PrOCl + HCl. However, our study indicates that PrCl₃ hydrolysis follows the schematic PrCl₃ → Pr(OH)₂Cl → PrOCl. In this study, several analytical techniques, such as X-ray diffraction, field-emission scanning electron microscopy (FESEM), thermogravimetry (TG)–differential thermal analysis (DTA) and TG–DTA–mass spectrometry, were employed to explore the mechanism underlying the thermal decomposition of PrCl₃·6H₂O at 25 – 1500 °C in air atmosphere. To examine the hydrolysis mechanism of PrCl₃, the hydrolysis product was separated by continuous centrifugation. The phase composition and morphology of the intermediate compound were determined by XRD and FESEM, respectively. Finally, the dehydration schematic and oxidation behavior of PrCl₃ were discussed according to the evolved gas composition.