Structural and textural properties of silica-magnesia and metal oxide impregnated silica-magnesia systems

ABSTRACT

Silica-magnesia systems of different chemical composition were prepared by coprecipitation. Li2O, NiO2, CoO3, La2O3 and Al2O3-impregnated silica-magnesia samples were also prepared. The samples were calcined in the temperature range 400-1000C. Surface area and pore structure were determined from nitrogen adsorption and the structural properties were determined from DTA and X-ray diffraction. The changes brought about by calcination and impregnation were characterized. Calcination above 600C causes a decrease in surface area and pore widening. Similar effects were also found by metal oxide impregnation. Li2O shows tremendous effect. It also initiates crystallization as indicated by sintering and new phase formation