Reducing the competitive adsorption between SO2 and NO by Al2O3@TiO2 core-shell structure adsorbent

The Al2O3@TiO2 core-shell structure adsorbent was designed, prepared, and used to reduce the competitive adsorption between SO2 and NO. The result showed that γ-Al2O3 and anatase were obtained in this study, and Al2O3 was well wrapped by TiO2 to form the core-shell structure. The Al2O3@TiO2 core-shell structure adsorbent with the core-shell mole ratio of 1:1 showed the best capacity of simultaneous desulfurization and denitrification, and the capacity was much better than Al2O3, Al2O3 + TiO2, and TiO2. NOx is easier to get though the pore of the shell material because of the smaller molecular diameter of NOx comparing with SO2, and the special structure of the core-shell adsorbent can be used to change the partial pressure of NOx and SO2 on the surface of the core material, thereby reducing the competitive adsorption. NO and SO2 would be catalytically oxidized to NO2 and SO3 on the shell structure, then SO3 was adsorbed by the shell material, and NOx was adsorbed by the core. Al–O and Ti–O were the adsorption sites, and the product of chemisorption was nitrate and sulfate radical.