An LiAl–layered double hydroxide (LiAl–LDH) was synthesized by autoclaving an aqueous solution of LiCl and AlCl3 with urea at 100–160 °C. Chemical and structural analyses show the resulting powder to be pure and well-crystallized LiAl2(OH)6(CO3)0.5·yH2O (1 < y < 2). X-ray powder diffrac- tion reveals an apparent monoclinic C2/m symmetry and the presence of disorder in the arrangement of the layers. A detailed study of the reaction is also proposed, demonstrating that the LiAl–LDH does not form by homogeneous precipitation, but is the result of a one-pot imbibition of the Al(OH)3 gel precursor by Li2CO3, favored by an increase in the pH.
Well-Crystallized CO32- -Type LiAl-LDH from Urea Hydrolysis of an Aqueous Chloride Solution
Leoni, Matteo;
2012-01-01
Abstract
An LiAl–layered double hydroxide (LiAl–LDH) was synthesized by autoclaving an aqueous solution of LiCl and AlCl3 with urea at 100–160 °C. Chemical and structural analyses show the resulting powder to be pure and well-crystallized LiAl2(OH)6(CO3)0.5·yH2O (1 < y < 2). X-ray powder diffrac- tion reveals an apparent monoclinic C2/m symmetry and the presence of disorder in the arrangement of the layers. A detailed study of the reaction is also proposed, demonstrating that the LiAl–LDH does not form by homogeneous precipitation, but is the result of a one-pot imbibition of the Al(OH)3 gel precursor by Li2CO3, favored by an increase in the pH.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione
