Degradation of chlorobenzene by non-thermal plasma coupled with catalyst: influence of catalyst, interaction between plasma and catalyst

Abstract

Non-thermal plasma (NTP) is considered to be a promising technology for the removal of volatile organic compounds; however, its application is limited by low CO2 selectivity and undesirable by-products. To overcome these issues, this paper discusses the degradation of chlorobenzene (CB) in systems of NTP coupled with catalysts, and the influence of catalyst locations in the NTP was investigated. In addition, the interaction between plasma and catalyst was also explored. The results indicated that the degradability of CB was remarkably improved through the combination of NTP with catalysts, and the formation of ozone was effectively inhibited. The degradation efficiency increased from 33.9% to 79.6% at 14 kV in the NTP-catalytic system, while the ozone concentration decreased from 437 to 237 mg m−3, and the degradation efficiency of in plasma catalysis (IPC) systems was superior to that of the post plasma catalysis system, while the inhibition ability of ozone exhibited an opposing trend. In the IPC system, the degradation efficiency was 87.7% at 14 kV, while the ozone concentration was 151 mg m−3. Besides, the plasma did not destroy the pore structure and crystal structure of the catalyst, but affected the surface morphology and redox performance of the catalyst. Thus, NTP coupled catalytic system could improve the degradation performance of CB. Furthermore, the plasma discharge characteristics played a major role in the NTP synergistic catalytic degradation of CB. Finally, based on the experiment analysis results, the general reaction mechanism of CB degradation in an IPC reaction system was proposed.