Revealing the Jahn–Teller Mitigating Complexity of Se-Anchored Mn Oxides for Superior SO<sub>2</sub> Resistance in Gaseous Molecular Oxygen Activation
Haomiao Xu, Qinyuan Hong, Jia’nan Wang, Jun Lei, Mingming Wang, Jiaxing Li, Zhisong Liu, Mingze Jiao, Wenjun Huang, Zan Qu, Naiqiang Yan
Abstract
Manganese oxides have emerged as promising catalysts for the low-temperature activation of molecular oxygen (O 2 ), crucial for the catalytic oxidation and removal of gaseous pollutants. However, the undesired Jahn–Teller (J-T) effects associated with the Mn iv /Mn iii redox couple, particularly under SO 2 poisoning, led to the effectiveness of Mn oxides in applications. Herein, we construct a highly covalent Se iv -O-Mn iii structure via the introduction of selenium into α-MnO 2 . Such a structure features high-valence Se iv anchored on the oxygen-terminated (110) plane of α-MnO 2, facilitates the generation of more active oxygen species, and maintains the continuous cycling of oxygen-linked Mn iv /Mn iii . Such dynamics are pivotal for stabilizing manganese activation and mitigating the J-T effect. Through a combination of experimental investigations and theoretical calculations, we demonstrate that the Se iv -O-Mn iii configuration, characterized by a high degree of Mn–O hybridization, significantly enhances CO oxidation, NH 3 oxidation, and elemental mercury (Hg 0 ) removal performances, and exhibits resistance to SO 2 . This study paves the way for the development of efficient low-temperature O 2 activation processes for the removal of gaseous pollutants in real-world applications.