Simultaneous Desulfurization and Denitrification on the SAPO-34@Al2O3 Core–Shell Structure Adsorbent

The SAPO-34@Al2O3 core–shell structure adsorbent was designed, prepared, and used to simultaneous desulfurization and denitrification. The SAPO-34@Al2O3 core–shell structure adsorbent showed better adsorption performance than SAPO-34, Al2O3, and SAPO-34 + Al2O3 for the core–shell structure. SAPO-34 was wrapped in irregularly shaped Al2O3, and the distribution of Al2O3 on the surface of SAPO-34 was uneven. The preparation of the core–shell structure presents an additional advantage of increasing the specific surface area. In comparison to MnOx and Fe2O3, SAPO-34 as the core material showed the best adsorption performance for the surface properties and pore structure of SAPO-34. SO2 and NO adsorption were mainly chemical adsorption, and Al2O3 played an important role in the adsorption process. NO and SO2 would be catalytically oxidized to NO2 and SO3 by Al2O3, and then most SO3 and a small amount of NO2 were adsorbed by shell material (Al2O3). The surface properties and pore structure of SAPO-34 made NO2 adsorb, while SO2 was blocked out of the core material. Al2O3 on the surface and pores of SAPO-34 could provide chemical adsorption sites, and the products of SO2 and NO adsorption were sulfate and nitrate.