Effective mineralization of p-nitrophenol by catalytic ozonation using Ce-substituted La1‒xCexFeO3 catalyst. (December 2021)

• Record Type: Journal Article
• Authors: Ren, Hongfei; Wang, Zexiang; Chen, Xiaoming; Jing, Zhenyang; Qu, Zhengjun; Huang, Lihui
• Is Part Of: Chemosphere. Volume 285(2021)
• Publication Date: 2021-12
• Subjects: Heterogeneous catalytic ozonation -- Perovskite -- Mineralization -- Catalytic mechanism; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.131473
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: In this study, cerium-doped lanthanum ferrite perovskite oxides (La1‒x Cex FeO3 ) with different A-site were synthesized using a sol-gel method and they were used as ozonation catalyst for p -nitrophenol (PNP) mineralization for the first time. Catalytic activity in terms of total organic carbon (TOC) removal followed the order of La0.8 Ce0.2 FeO3 > La0.4 Ce0.6 FeO3 > La0.6 Ce0.4 FeO3 > La0.2 Ce0.8 FeO3 > LaFeO3 with 77, 66, 61, 60 and 56% respectively. The synthesized catalysts were characterized by diffraction of X-ray (XRD), Raman spectroscopy, Brunauer-Emmett-Teller (BET) and scanning electronic microscopy (SEM). Moreover, electron spin resonance (ESR) and radicals quenching experiments showed that the active oxygen species in the ozone decomposition process are mainly hydroxyl radical (·OH), and also include superoxide radical (O2 − ) and singlet oxygen ( 1 O2 ). Furthermore, the superior activity of La0.8 Ce0.2 FeO3 could be attributed to the higher surface area, the richer lattice oxygen, richer surface –OH groups and the facilitated redox Ce 3+ /Ce 4+ and Fe 2+ /Fe 3+ cycling. In addition, this study provides an insight to use metal-doped perovskite catalysts for catalytic ozonation. Highlights: The La1−x Cex FeO3 catalysts were synthesized and used as ozonation of PNP. La0.8 Ce0.2 FeO3 catalyst showed the highest activity for catalytic ozonation. Generated reactive species, ·OH, ·O2 − and 1 O2, were possible for PNP degradation. Surface lattice oxygen is crucial for chemical looping.