A Sm‐Modified α‐Mn ₃ O ₄ Integrated Catalytic Filter Bag for Low‐Temperature Selective Catalytic Reduction Denitrification

ABSTRACT Sm/MnO x composite catalysts were prepared by the citric acid (CA) sol–gel method and impregnated it on polytetrafluoroethylene (PTFE) filter bags under its optimizing preparation conditions to obtain the catalytic filter bag (CFB‐Sm), and applied it for NH 3 ‐SCR (selective catalytic reduction) of industrial kiln flue gas. The results showed that Sm/MnO x composite had an excellent denitrification activity and excellent resistance to H 2 O and H 2 O. When the Sm/Mn molar ratio of 0.08 and calcination temperature of 400°C, the NO was 500 ppm, the NO conversion rate reached 100% at 150°C, the NO conversion rate of CFB‐Sm reached 86% at 225°C. Compared with bare α‐Mn 3 O 4 , NO conversion rate of the Sm(0.08)/MnO x (400) increased about 80% after adding H 2 O and SO 2 . Sm reduced the apparent activation energy of Sm(0.08)/MnO x (400), increased the overall reaction rate and enhanced H 2 O and SO 2 resistance. Doping of Sm increased the specific surface area, surface‐adsorbed oxygen, and adsorption sites could promote denitrification at low temperatures.