关键词: 低温等离子体, 氯苯, Mn基催化剂, 前体, 臭氧

Abstract:

Chlorobenzene (CB), a typical representative of chlorinated volatile organic compounds (CVOCs), was selected as the research object. Mn based catalysts were prepared by impregnation method with manganese nitrate (MN) and manganese acetate (MA) as precursors, respectively. The effects of non-thermal plasma cooperating with Mn based catalysts on the degradation of CB and the inhibition of ozone generation, a by-product of the reaction, were investigated. It is found that increasing the discharge voltage can improve the degradation efficiency of CB for different reaction systems. The introduction of catalyst can greatly improve the degradation performance of CB. Compared with MnO _x (MN)/γ-Al₂O₃, the introduction of MnO _x (MA)/γ-Al₂O₃ has better degradation effect and higher inhibition performance on ozone generation. The catalysts before and after the reaction were characterized by N₂ adsorption-desorption, scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). It was found that the discharge had no effect on the pore size and crystal structure of the catalyst. The variation of Cl elements during the degradation of CB were analyzed by Cl selectivity and tail GC-MS. Compared with MnO _x (MN)/γ-Al₂O₃ catalyst, the specific surface area of ​​the MnO _x (MA)/γ-Al₂O₃ catalyst is relatively large, and the active components have higher and more uniform dispersion, resulting in more ozone of the reaction system being decomposed into active oxygen atoms on the catalyst surface, which improves the degradation performance of CB and inhibits the formation of ozone in the reaction system.

Key words: non-thermal plasma, chlorobenzene, Mn based catalyst, precursor, ozone