Simultaneous removal of CO, NOx, and HC emitted from gasoline engine in a nonthermal plasma-driven catalysis system

The performances of nonthermal plasma-driven catalysis system (NTP-C) for real gasoline engine tail gas purification were studied with different supported catalysts (i.e. La_0.8-K_0.2MnO_x/5A, La_0.8-K_0.2MnO_x/γ-Al₂O₃, La_0.9-K_0.1CoO_x/5A, and La_0.9-K_0.1CoO_x/γ-Al₂O₃) prepared by a high-temperature solid state reaction method. To clarify the effectiveness of the NTP-C system, a NTP reactor was employed, which has the same inner structure as the NTP-C but without catalyst. The removal efficiency of studied pollutants is following the order of HC->-NOx->-CO in all NTP-C coupling system. Active phase component has crucial effects on the removal efficiency of pollutant. NTP coupled with La_0.9-K_0.1CoO_x/5A catalyst shows the best pollutant removal efficiency with 65%, 75%, and 85% of CO, HC, and NOx converted at 1400-J/L, respectively. Oxygen content in the tail gas has significant influences on pollutant decomposition, and the active oxygen atom makes a vital contribution to the higher HC removal efficiency. It can be expected that lots of chemical reactions induced by multicomponent precursors in practical vehicle tail gas reduce the pollutant removal efficiency, especially for CO and NOx.