Addition of V 2 O 5 -MnO 2 /USY-zeolite catalyst in PTFE fiber for bag filter and its catalytic activity tests for NH 3 -SCR at low-temperature

This study investigated the catalytic activity of vanadium-manganese supported on USY-zeolite as a catalyst for low-temperature NO removal, and embedded the powder catalyst in PTFE filter of bag filter. The V 2 O 5 -MnO 2 /USY-zeolite catalyst was prepared using the co-impregnation method, and the V 2 O 5 /MnO 2 ratio was 0/10, 2.5/7.5, 5/5, 7.5/2.5, or 10/0. The catalytic activity test for NH 3 -SCR(selective catalytic reduction) of NO was performed at 150–230 °C. An enhanced NO conversion above 60% was exhibited in the low-temperature region below 230 °C, and the NO removal efficiency increased as the MnO 2 content increased. The NH 3 -TPD and NO-TPD(Temperature Programmed Desorption) analysis confirmed that the NH 3 adsorption of the catalyst more significantly influences the NO removal performance than the NO adsorption. As the MnO 2 content on the catalysts increased, the strength and amount of adsorbed NH 3 increased, resulting in enhanced NO conversion. The catalyst-embedded PTFE (polytetrafluoroethylene) fiber was prepared by extruding physically mixed PTFE and catalyst powder. Scanning electron microscopy/energy dispersive X-ray spectroscopy confirmed that the catalyst was well dispersed on the surface and inside the PTFE fiber. The NO removal performance of the catalyst included PTFE fiber increased as the amount of the catalysts added was increased.