Development of high-performance SO2 trap materials in the low-temperature region for diesel exhaust emission control

• HSSA MnO2 is focused on as candidate materials for desulfurization filters.
• The SO2 capture capacity increases with increasing surface area at low temperature.
• The effect of temperature on sulfate rate can be explained by grain model.
• The gradient of sulfate rate constant decreases with increasing reaction temperature.

Growing concern about sulfur dioxide (SO2) poisoning NOx removal catalysts has resulted in the development of desulfurization materials for SO2 trap. In this study, a series of high-specific-surface-area manganese oxide (HSSA MnO2) were selected as desulfurization materials and characterized by nitrogen adsorption and SEM. HSSA MnO2 has good SO2 capture performance over a wide temperature range. At low temperature, SO2 capture capacity and adsorption rate increase with the specific surface area and HSSA MnO2 showed high SO2 capture performance. The effect of temperature on sulfate rate of HSSA MnO2 can be explained by the grain model. The gradient of sulfate rate constant decreases with increasing the reaction temperature, and there is a sudden drop at 500 °C. The SO2 capture performance of regenerated HSSA MnO2 decreases sharply because of physical damage by calcination at high temperature.