Plasma-catalytic destruction of benzene in a hybrid surface/packed-bed discharge over AGxCE1−x/γ-AL2O3 catalyst

Summary form only given. A hybrid surface/packed-bed discharge (HSPBD) plasma reactor has been developed for plasma-catalytic degradation of benzene over different Ag_xCe_1-x/γ-Al₂O₃ catalysts. The Ag_xCe_1-x/γ-Al₂O₃ catalysts were combined with surface discharge plasma and packed-bed discharge plasma in in-plasma catalysis (IPC) and post-plasma catalysis (PPC) configurations, respectively, to investigate the effect of catalysts packed into different plasma regions on discharge characteristics and determine consequent synergistic effects in the plasma-catalytic destruction reactions. In addition, the effect of active metal component ratio (Ag/Ce atomic ratio) on the activities of catalysts for benzene degradation was also investigated. The experimental results showed that the catalytic performance of Ag_xCe_1-x/γ-Al₂O₃ catalysts for benzene was strongly dependent on catalyst location. Almost complete destruction of benzene was achieved when the catalysts is placed downstream the packed-bed discharge region, but the catalysts packed into the packed-bed discharge region showed better promotional effect in CO₂ selectivity. The catalyst activities for the benzene degradation and CO₂ selectivity decreased in the following order: Ag_0.9Ce_0.1/γ-Al₂O₃> Ag_0.7Ce_0.3/γ-Al₂O₃> Ag_0.5Ce_0.5/γ-Al₂O₃> Ag/γ-Al₂O₃> Ag_0.3Ce_0.7/γ-Al₂O₃> Ag_0.1Ce_0.9/γ-Al₂O₃. Furthermore, the ozone produced by the plasma is able to dissociate on the surface of Ag_xCe_1-x/γ-Al₂O₃ cataly- t, thereby creating peroxide surface groups which greatly improve the decomposition of benzene.