Some Studies on the Synthesis and Surface Properties of Mixed Oxides of Alumina and Magnesia

A series of mixed oxides of alumina and magnesia with different MgO contents were prepared by wet impregnation method. The synthesized mixed oxides Al2O3-MgO were characterized with X-ray diffraction (XRD), FESEM, Fourior Transform infrared (FTIR), Thermogravimeric analysis (TGA), and BET methods. The point of zero of mixed oxides was determined by salt addition method to explore the effect of MgO contents on the PZC of commercial Al2O3. The activation energies of thermal decomposition for different Mg (NO3)(2)center dot 6H(2)O loading onto Al2O3 was determind by Freidman model. The results showed the as the MgO loading was increased the PZC of alumina was also increased linearly. Moreover, the PZC of these synthesized mixed oxides varied between the PZCs of pure oxides of Al2O3 and MgO. Further, it was noted that alumina retained its structure when the MgO content was low however, high loading of MgO caused change in the phase and structure of alumina. Activation energy, of thermal degradation increased as the Mg (NO3)(2)center dot 6H(2)O loading was increased onto Al2O3.