Synthesis of CeO2Fe2O3 nanocomposites via controllable oxidation of CeFeO3 nanocrystals

Abstract

Abstract This work presents an innovative way of preparation preceramic nanocomposites based on CeO2 and Fe2O3 with an extremely low surface area (0.027–0.262 m2/g) and pore volume (0.4–5.0·10−4 cm3/g). Preceramic nanocomposites were synthesized by the high-temperature oxidation of CeFeO3 nanocrystals in the air. Crystals of CeO2 and Fe2O3 in nanocomposites have a spherical morphology with an average crystallite size of 4–6 nm and 40–47 nm for 700 and 900°С treatment temperatures correspondingly. Fine ceramics based on the CeO2 and Fe2O3 with submicron grain size were obtained via sintering of the compacted preceramic nanopowders at 1000°С for 4 h. It was shown that depending on the synthesis temperature of the preceramic nanocomposites ceramics with low (0.7–1.0 W/m·K) and high (2.3–4.3 W/m·K) thermal conductivity in the temperature range of 25–600°С can be obtained. So, a novel approach for the synthesis of CeO2/Fe2O3-based ceramics with controlled heat-conducting properties was proposed. The resulting ceramics can be considered as the perspective material for chemical-looping steam methane reforming (CL-SMR).