Enhanced low-temperature Selective Catalytic Reduction (SCR) of NOx by CuO-CeO2-MnOx/gamma-Al2O3 mixed oxide catalysts

摘要

A series of CuO-MnOx-CeO2/gamma-Al2O3 catalysts in different ratios were synthesized by a sol-gel method with the purpose of improving the low-temperature denitration performance (loading a transition mental oxide (MnOx, CeO2) on a CuO/gamma-Al2O3 copper-based catalyst). The denitration performance of a low-temperature SCR under the condition of simulated flue gas was measured using the programmed heating method in the catalytic reaction efficiency evaluation system. The denitration efficiency of the 6 % CuO-5 % MnOx-10 % CeO2/gamma-Al2O3 catalytic particles was maintained at over 80 % within a temperature range of 100-200 degrees C. The catalysts were characterized by surface area analysis (BET), x-ray diffraction (XRD), and scanning electron microscopy (SEM). The best surface structure characteristics include the 5 % MnOx + 10 % CeO2 loading capacity of the catalyst, which was indicated by a BET analysis. The catalyst surface structure characteristics were effectively promoted by the amount of CeO2 and MnO2 loading proved by the SEM analysis. The possible mechanisms involved in SCR denitration at a low temperature were also discussed. The experimental results revealed that the catalyst granule with perfect surface characteristics and pore features was successfully synthesized by the sol-gel method. The denitration performances were restrained by 10 % of H2O and 800 mg center dot m(-3) of SO2, indicating that SO2 and H2O have an inhibiting effect on NOx conversion.