Catalytic behavior and synergistic effect of nonthermal plasma and CuO/AC catalyst for benzene destruction

Nonthermal plasma-catalysis hybrid technology (NTP-C) operated at ambient temperature and pressure offers an innovative and effective approach to solving the problem of dilute volatile organic compounds pollution. Herein, the destruction of benzene (50–450 ppm) over an in-plasma NTP-C composite system was investigated. The AO_x/active carbon (AO_x/AC), AO_x/3A molecular sieve (AO_x/MS), and AO_x/γ-Al₂O₃ (A = Fe, Ag, Zn, Mn, and Cu) catalysts were prepared by the incipientwetness impregnation method. The destruction performances of NTP alone and NTP-C are compared under different reaction conditions, such as inlet reactant concentration, catalyst type, and energy density. AC exhibits the best benzene removal efficiency among three catalyst supports, and the performances of AO_x/AC under different conditions follow the trend of CuO/AC>MnO/ AC>MnO₂/AC>Fe₂O₃/AC[AC>ZnO/AC>Ag₂O/AC. The NTP with CuO/AC system exhibits the highest benzene elimination capability with almost 90.6 % inlet benzene removed at energy density of 70 and 270 J L^-1. The strong adsorption ability of AC and the optimal catalytic ability of crystalline structure of CuO on the AC support may be contributed to the excellent performance of CuO/AC. It is found that the NO_x by-product also can be well controlled over NTP-CuO/AC system. Additionally, the surface of CuO/AC is more slipperier and homogeneous with the reaction proceeding, indicating higher stability of CuO/AC.

Keywords
Nonthermal plasma; Benzene; CuO/AC; Reaction conditions; Synergistic effect