Carbochlorination of cerium dioxide

Abstract

The kinetics of the chlorination of CeO₂(s)–C(s) powder mixtures in flowing Ar(g)–Cl₂(g) were studied by thermogravimetry between 700°C and 950°C. The effects of temperature, total gas flow rate, sample mass and carbon content were analysed. The carbochlorination rate and the reaction degree obtained at a given time increased with higher temperature, faster gas flow rate and larger proportion of carbon. The reaction rate was found to be influenced by mass-transfer processes. The presence of carbon was crucial to the formation of gaseous intermediates. The effect of the temperature in the vaporization of condensed products was significant. Solid reactants (CeO₂ and C) and condensed products (CeCl₃) and remaining reactants (C) were identified and characterized by X-ray diffraction, energy-dispersive spectroscopy and scanning-electron microscopy techniques.

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