Influence of residual anions (Cl-, SO42- and NO3-) on Mn2O3 for photothermal catalytic oxidation of toluene. Issue 5 (October 2022)

• Record Type: Journal Article
• Authors: Yu, Xiao; Deng, Banghong; Yang, Lixia; Zou, Moliang; Chen, Zhenglin; Fan, Yixuan; Wei, Zhihui; Chen, Kai; Lu, Mingxia; Ying, Tiantian; Zhang, Jie; Dai, Weili
• Is Part Of: Journal of environmental chemical engineering. Volume 10:Issue 5(2022)
• Publication Date: 2022-10
• Subjects: Toluene -- Mn2O3 -- Photothermal catalytic degradation -- Poisoning effect; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2022.108496
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: Mn2 O3 is a conventional catalyst that is applied in photothermal catalytic oxidation of toluene while regular anions like SO4 2-, Cl -, and NO3 - from different Mn precursors are left in Mn2 O3 . When applied in toluene degradation, the declining activity of Mn2 O3 is always observable because the residual anions block the Mn 4+ /Mn 3+ active sites, shield the oxygen vacancies, and cube the production of active oxygen species (O2 -, O - ). Herein, it is found that the residual SO4 2-, Cl -, and NO3 - make Mn2 O3 incapacitated in deeply oxidizing the intermediates and cutting off the reaction process, and their influence ranks in the order of SO4 2- >Cl - >NO3 - . Compared with pristine Mn2 O3, the drops in CO2 conversion efficiency account for 11 %, 60 %, and 73 %, respectively. Nevertheless, rinsing with water is an effective method to remove the residual anions, and the more the rinsing, the better the toluene mineralization degree. This work provides a profound cognition of the deactivation mechanism of SO4 2-, Cl -, and NO3 - and points out an effective way to abate their negative effect for the first time. Graphical Abstract: ga1 Highlights: NO3 - poses a neglectable impact on Mn2 O3 's catalytic activity. SO4 2- and Cl - anions cover the OVs and active sites, causing reduced catalytic properties. Multiple rinsing washes the anions away from MnC2 O4 to endow high activity of Mn2 O3 .