Addition of V₂O₅-MnO₂/USY-zeolite catalyst in PTFE fiber for bag filter and its catalytic activity tests for NH₃-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 V₂O₅-MnO₂/USY-zeolite catalyst was prepared using the co-impregnation method, and the V₂O₅/MnO₂ ratio was 0/10, 2.5/7.5, 5/5, 7.5/2.5, or 10/0. The catalytic activity test for NH₃-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 MnO₂ content increased. The NH₃-TPD and NO-TPD(Temperature Programmed Desorption) analysis confirmed that the NH₃ adsorption of the catalyst more significantly influences the NO removal performance than the NO adsorption. As the MnO₂ content on the catalysts increased, the strength and amount of adsorbed NH₃ 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.