# Chlorobenzene Removal Using DBD Coupled with CuO/\(\gamma\)-Al\({}_{2}\)O\({}_{3}\) Catalyst
## 1 Introduction  
Chlorinated volatile organic compounds (CVOCs) exist in various environmental matrices such as air, water, sand, clay, and sludge [1; 2; 3]. Due to its high volatility and strong recalcitrance to degradation, CVOCs are more toxic than other VOCs and their environmental lifetime is longer [4; 5]. Therefore, most CVOCs have been listed as priority pollutants by many countries with strict monitoring. However, CVOCs have been widely used in industry as organic solvents for processes such as metal degreasing and dry cleaning [6; 7; 8]. Various commercial products containing CVOCs and the main sources of CVOCs principally include industrial emissions, the consumption of CVOC-containing products, the disinfection process, as well as improper storage and disposal operation [9]. Thus, the control of CVOCs has drawn the attention of many investigations. In recent decades, the study of CVOCs control mainly focused on the adsorption method [10; 11; 12; 13; 14; 15], photo-degradation [16; 17; 18], combustion treatment [19; 20], biodegradation [21; 22] and catalytic oxidation [23; 24; 25; 26; 27]. However, the adsorption method only presents a temporary pollution transfer from the gaseous to the solid phase, requiring further treatment for the adsorbents. The use of photo-degradation is limited by the stability of the lightsource and slow reaction rate, while the combustion treatment requires high combustion temperatures as well as huge energy consumption. The catalytic oxidation method is also limited by a high and narrow temperature window for the complete treatment of CVOCs. Moreover, some studies indicated that the catalytic oxidation of chlorobenzene in high temperatures might produce undesired products such as polychlorinated benzene [28; 29]. As a destructive method, the efficiency of non-thermal plasma technology (NTP) treating VOCs has been proved by many studies [30; 31; 32]. However, the application of NTP is limited by its drawbacks, such as low selectivity and the production of unwanted products. Therefore, many studies focus on the hybrid technologies of NTP coupled with other technologies [33; 34; 35; 36]. Among these hybrid systems, plasma catalysis technology shows its advantages among the treatments of typically VOCs for its high selectivity and removal rate because the gas-phase reaction and catalyst surface reaction induces a synergistic effect of plasma and catalysts [37; 38; 39; 40; 41]. In previous studies, the enhancing effect of various transition metal oxides for the treatment of VOCs by NTP has been confirmed. Among them, copper-based catalysts have received extensive attention due to their relatively low cost and high reactive activity. [PERSON] et al. reported that the supported copper oxide catalyst showed the optimal acetone degradation ability in a catalyst-enhanced DBD system [42]. In another study, the supported copper oxide catalyst exhibits a better performance assisted NTP system for benzene treatment among five transition metal oxides [43]. Moreover, the copper-based catalysts are also capable of catalyzing the CO oxidation reaction, which helps to improve the CO\({}_{2}\) selectivity of VOC degradation. [PERSON] et al. used catalytic CuO nanowires enhanced by plasma catalyzing CO oxidation [44]. Those results showed that on the surface of copper-based catalysts, Cu\({}^{2+}\) ions not only act as a catalyst for the oxidation of CO but also act as a reducing agent for CO oxidation under oxygen-poor conditions. During the plasma treatment, some of the Cu\({}^{2+}\) ions can be partially reduced to Cu\({}^{+}\) ions, which has a stronger catalytic ability when catalyzing CO oxidation. Although the capacity of copper-based catalyst-assisted cooperative plasma treatment of VOC has been proved [45; 46; 47], there are few reports focus on copper-based catalyst-assisted plasma treatment of CVOC [48].