Theoretical study on the microstructures of hydrotalcite lamellae with Mg/Al ratio of two

The microstructures of lamellae of hydrotalcites with Mg/Al ratio of two are studied using quantum chemical method. A series of molecular cluster models of lamellae are established. The geometries of lamellae are computed by semiempirical molecular orbital methods (MNDO/d and PM3). The optimized cluster models show a hexagonal morphology. The Mg/Al ratio of lamella is found to be an alterable number and its limit is two when the lamella diameter becomes large. The molecular orbital calculations show that the edge and the center of lamellae are respectively easy to attract cations and accept anions, to form intercalated structure.