Novel application of sodium manganese oxide in removing acidic gases in ambient conditions

Abstract In this study, we have demonstrated the application of sodium manganese oxide for the chemisorption of toxic acidic gases at room temperature. The fabricated alkali ceramic has Na 0.4 MnO 2 , Na 2 Mn 3 O 7 , and Na x MnO 2 phases with a surface area of 2.6 m 2 g –1 . Na-Mn oxide was studied for oxidation of H 2 S, SO 2 , and NO 2 gases in the concentration range of 100–500 ppm. The material exhibited a high uptake capacity of 7.13, 0.75, and 0.53 mmol g –1 for H 2 S, SO 2 , and NO 2 in wet conditions, respectively. The material was reusable when regenerated simply by soaking the spent oxide in a NaOH-H 2 O 2 solution. While the H 2 S chemisorption process was accompanied by sulfide, sulfur, and sulfate formation, the SO 2 chemisorption process yielded only sulfate ions. The NO 2 chemisorption process was accomplished by its conversion to nitrite and nitrate ions. Thus, the present work is one of the first reports on alkali ceramic utilization for room-temperature mineralization of acidic gases.