Effects of temperature on NOx removal with Mn-Cu/ZSM5 catalysts assisted by plasma

Abstract

Manganese-copper catalysts are well-known catalysts for selective catalytic reduction (SCR) of NOx. To evaluate the NOx removal in the combination system of catalysts and plasma, a series of Cu-Mn/ZSM-5 catalysts with varying amounts of manganese doping were synthesized by an incipient wetness impregnation method and used for SCR of NOx assisted by plasma at different temperatures. The results showed that the combination of catalyst and plasma promoted NO removal efficiency, the introduction of Mn on Cu/ZSM5 enhanced the catalyst activity, and 12Mn-12Cu/ZSM5 exhibited the best NO removal performance with about 90% NO removal efficiency at 25 °C. With a rise in temperature, the reduced electric field (E/N) increased, intensifying the discharge and generating more active radicals. In the absence of catalyst, an increase in the temperature had a negative effect on NO removal due to the reduction of the predominant oxidant O3. However, when the temperature increased in the combination system, NO removal efficiency decreased below 100 °C, while increased above 100 °C, which increased dramatically at low discharge power above 150 °C.