Controlled Synthesis of Lithium Zirconates with Different Crystalline Phase
Xian-Sheng Yin, Guo-Ping Xiao, Qin-Hui Zhang and Jian-Guo Yu
The LixZryOz compounds, including pure monoclinic-phase Li2ZrO3, triclinic and monoclinic-phase Li6Zr2O7, high-purity tetragonal-phase Li2ZrO3 and rhombohedral- phase Li8ZrO6 were synthesized by solid-state reaction method. The influences of different reagents, calcination temperature and time on the product of LixZryOz were investigated via X-ray diffraction (XRD), and the properties of CO2 adsorption were also tested by the reactive Thermo-gravimetric (TG) analysis. The results indicated that monoclinic-phase Li2ZrO3 was the main product if Li2CO3 and ZrO2 used as the initial reagents; when Li2CO3 was substituted with LiOH, tetragonal and monoclinic- phase Li2ZrO3, triclinic and monoclinic-phase Li6Zr2O7 could be produced at suitable conditions, respectively; with replacing ZrO2 by Zr(NO3)4, the synthesis time for monoclinic-phase Li6Zr2O7 could be shorten greatly, and high-purity rhombohedral- phase Li8ZrO6 could be produced at enough Li/Zr molar ratio. The CO2 adsorption test indicated that each of the synthesized LixZryOz products has definite CO2 capture capacity.
Keywords: controlled synthesis, lithium zirconates, solid-state reaction method, re-crystallization, crystal phase, CO2 adsorption.