CO2 absorption of CeO2-coated α-LiFeO 2

Abstract

α-LiFeO2 columnar particles were synthesized by heating a mixture of γ-Fe2O3 and LiNO3 at 500°C in air. CeO2 nanoparticles were prepared from Ce(OH)3 obtained by a precipitation method. The α-LiFeO2 columnar particles were mixed with the CeO2 nanoparticles in an aqueous solution and then the mixture of α-LiFeO2 and CeO2 was heated at 300°C to prepare the α-LiFeO2 coated with CeO2 nanoparticles. Then the effect of CeO2 coating on CO2 absorption ability of α-LiFeO2 was investigated. As a result, coating of CeO2 on α-LiFeO2 particles was found to suppress the structural phase transition of α-LiFeO2 to β-LiFeO2, although the synthesized α-LiFeO2 underwent a structural phase transition of α-LiFeO2 to β-LiFeO2 accompanied by the reaction of α-LiFeO 2 with CO2 in the temperature range of 350 to 425°C. The suppression of the structural phase transition resulted in an increase in CO2 absorption rate of LiFeO2 in the temperature range up to 425°C. Thermodynamic analysis revealed that the α-LiFeO2 phase has a lower activation energy for CO2 diffusion than the β-LiFeO2 phase, which results in the enhancement of the CO 2 absorption rate of LiFeO2. © 2011 The Ceramic Society of Japan.