[Preparation by different methods and characterization of desulfurization mixed oxides derived from hydrotalcites]

Hydrotalcite-based MgAl mixed oxides were synthesized by urea hydrolysis and constant-pH coprecipitation methods, and characterized by means of X-ray diffraction (XRD) , thermal gravity analysis-differential thermal gravity (TG-DTG) , scanning electron microscope (SEM), N2-adsorption/desorption and CO2 temperature programmed desorption (CO2-TPD), and their adsorption performances for SO2 were also tested. It was found that MgAl mixed oxides prepared by coprecipitation method would facilitate the catalyst to maintain a high specific area (148. 1 m2.g-1) and more basic sites, which resulted in higher SO2 adsorption capacity and velocity. The SO2 adsorption capacity of the mixed oxides prepared by urea hydrolysis and constant-pH coprecipitation methods were 0.55 g.g-1and 0. 79 gg-1 respectively at 700 degreeC.