Production and characterisation of LDH meixnerite powders

Abstract

Meixnerite, which is a magnesium-aluminium hydrotalcite compound, is a hydrotalcite group mineral material with double layer structure. Recently, to prevent the environmental pollution caused by greenhouse gases, especially CO2, studies for production of synthetic meixnerite have been carried out. Meixnerite releases water vapour to the environment and reduces the CO2 emission by replacing airborne CO2 with OH groups present in its double layered structure through the adhesion of CO2 on itself. The present study covers the synthesis and characterisation of meixnerite by sol-gel method. Aluminium-isopropoxide and magnesium-chloride-hexahydrate were used as initial materials. First, boehmitic sol was prepared using sol-gel method. The mixture was stirred vigorously after adding magnesium-chloride-hexahydrate into the boehmitic sol. The mixture obtained after the gelation process was heat-treated at 550, 1300, 1400 and 1500 degrees C. The material which has [Mg5Al3(OH)(16)][(OH)(3)center dot 4(H2O)] chemical structure was determined as meixnerite which is a member of LDH group and used as CO2 reducer.