Preparation and desulfurization performance of various MnOx materials for ship exhaust emissions control

Sulfur dioxide (SO 2 ) emissions from ship exhaust pose a serious threat to the environment and human health. In this study, various manganese oxide (MnO x ) samples with different physical and chemical structures were prepared using template, precipitation, ball milling, calcination, and microwave methods for the desulfurization of ship exhaust. The MnO x samples were characterized intensively through scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Brunauer-Emmett-Teller analysis. The desulfurization performance was measured via thermogravimetry, and the desulfurization mechanism of the different MnO x samples was investigated. Results showed that the desulfurization performance of MnO x was determined by the comprehensive influence of the material’s pore structure, specific surface area, crystal structure, Mn valence content, and reaction temperature. The pore structure in MnO x considerably affected the desulfurization performance of MnO x . In our experiment, tp-MnO x prepared using the template method presented a rich 3D pore structure, a large specific surface area, and excellent desulfurization performance. At 400 °C, the average SO 2 capture rate of tp-MnO x in the first hour was 0.283 g SO2 /g material ·h. The highest SO 2 capture rate of tp-MnO x was 0.694 g SO2 /g material observed at 500 °C.