Preparation of lanthanum cerate powders via a simple molten salt route

Abstract Lanthanum cerate (La 2 Ce 2 O 7 ) powders were synthesized via a simple molten salt route using cerium oxide (CeO 2 ) and lanthanum oxide (La 2 O 3 ) as raw materials, and KCl–LiCl, Na 2 CO 3 –K 2 CO 3 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 La 2 Ce 2 O 7 formation were investigated. Among the three combined salts, NaCl–KCl–NaF showed the best accelerating effect on the La 2 Ce 2 O 7 formation. Phase pure La 2 Ce 2 O 7 particles with sizes of 2–5 μm were obtained after 3 h 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 La 2 Ce 2 O 7 particles. The “dissolution–precipitation” mechanism is believed to have played a key role in the synthesis process.