Preparation of lanthanum cerate powders via a simple molten salt route

Abstract

Lanthanum cerate (La2Ce2O7) powders were synthesized via a simple molten salt route using cerium oxide (CeO2) and lanthanum oxide (La2O3) as raw materials, and KCl–LiCl, Na2CO3–K2CO3 and NaCl–KCl–NaF to form the reaction media. The effects of different processing parameters such as reaction temperature, salt type and salt/reactant ratio on the La2Ce2O7 formation were investigated. Among the three combined salts, NaCl–KCl–NaF showed the best accelerating effect on the La2Ce2O7 formation. Phase pure La2Ce2O7 particles with sizes of 2–5μm were obtained after 3h firing at 1100°C in NaCl–KCl–NaF using the salt/reactant ratio of 3.0:1.0. Use of an appropriately higher amount of molten salt was beneficial to the formation of finer La2Ce2O7 particles. The “dissolution–precipitation” mechanism is believed to have played a key role in the synthesis process.