Selective ozone catalyzation modulated by surface and bulk oxygen vacancies over MnO2 for superior water purification

• Published in: Applied catalysis. B, Environmental Environmental, 2024-04, Vol.343, p.123526, Article 123526
• Main Authors: Wu, Liying, Wang, Zonglin, Liu, Jiaye, Liu, Caihong, Li, Xueyan, Zhang, Yixuan, Wang, Wei, Ma, Jun, Sun, Zhiqiang
• Format: Article
• Language: English
• Subjects: Electron transfer process; Hydroxy radical; Oxygen vacancy; Selective catalytic ozonation; Spatial position
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2023.123526

The regulation behavior of oxygen vacancies (Vo) at different spatial positions (surface or bulk) in catalysts for selective O3 catalyzation, along with the reaction pathways evolution was well-investigated in α-MnO2−x/O3 systems. Combined characterization methods, systematic organic removal experiments, structure-activity relationship analysis, and theoretical calculations were employed to unveil O3 decomposition and electron transfer behaviors regulated by surface or bulk Vo. The contribution of electron transfer process (ETP) to atrazine (ATZ) removal was reinforced from 5.2 % to 34.8 % with the formation of bulk Vo, and Vo-rich α-MnO2−x-2/O3 system achieved ∼96.5 % ATZ removal along with improved TOC mineralization (∼38 % vs. ∼20 %). Surface Vo facilitated O3 adsorption, promoting its decomposition into •OH, while bulk Vo not only accelerated •OH production but also withdrew electrons from organics to build ETP. This study shed light on precise modification of metal-based catalysts with Vo to modulate •OH/ETP synergistic processes in catalytic ozonation for efficient water purification. [Display omitted] •Rational Vo modification in catalysts promoted selective ozone catalyzation.•The reaction pathways (•OH and ETP) were modulated by surface and bulk Vo.•Both surface and bulk Vo boosted electrons transfer to decompose O3 into •OH.•Bulk Vo preferred to withdraw electrons from the organics to build ETP.••OH and ETP synergistic process facilitated the stoichiometry efficiency of O3.