In this study, two perovskite-type oxides, LaFeO3 and LaCoO3, were synthesized by a sol-gel method and characterized with nitrogen adsorption-desorption measurements, X-ray diffraction (XRS) analysis, field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM), and X-ray photoelectron spectroscopy (XPS). The catalytic ozonation performance of LaFeO3 and LaCoO3 for the degradation of benzotriazole (BZA) and elimination of bromate (BrO3−) was evaluated. LaFeO3 showed no catalytic activity for BZA degradation but inhibited the generation of BrO3− by 73% at 20 min compared with single ozonation. LaCoO3 exhibited significant catalytic activity for BZA degradation, with complete degradation achieved at 15 min compared with 20 min for single ozonation, and about 71% BrO3− inhibition at 20 min. Reactive oxygen species (ROS) such as H2O2 and hydroxyl radicals were identified during the catalytic ozonation by UV-visible and fluorescence spectroscopy. Important intermediates including HOBr/OBr−, NO3−, and intermediates containing carbon/nitrogen were also analyzed. Based on the obtained results, two reaction mechanisms of BrO3− formation/BZA degradation were proposed for LaFeO3 and LaCoO3, respectively. Here, a novel BrO3− elimination pathway in catalytic ozonation was proposed.

Comparison of catalytic ozonation by LaFeO3 and LaCoO3: Benzotriazole degradation, elimination of bromate andreaction mechanism

253rd National Meeting (2017)

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