Removal of NO by Using NaS 2 O 8 Solution: Catalyzed by Fe‐Doped MnO 2

In this study, NO was oxidized and absorbed by using Na 2 S 2 O 8 solution catalyzed by mesoporous Fe‐doped MnO 2 . Experimental results revealed that FeMn‐2 exhibited optimal performance, achieving 89.4% NO removal at a loading of 4 g/L. According to the XRD, BET, SEM, TEM, and XPS analysis results, the excellent catalytic performance of FeMn‐2 was ascribed to its low crystallinity, high surface area, and abundant surface oxygen vacancies. Furthermore, Mechanistic studies were investigated by using XPS and EPR techniques. It could be found that the redox cycle of Mn 3+ /Mn 4+ existed in the catalytic decomposition process of Na 2 S 2 O 8 , and Fe doping enhances the generation of oxygen vacancies, which accelerated the redox cycle between Mn 3+ and Mn 4+ . Additionally, free radical analysis experiments indicated that the existence of sulfate ( . SO 4 − ) and hydroxyl ( . OH) radicals promoted the oxidation and absorption of NO, where sulfate radical played the leading role.