Enhanced low‐temperature Selective Catalytic Reduction (SCR) of NO_x by CuO‐CeO₂‐MnO_x/γ‐Al₂O₃ mixed oxide catalysts

Abstract

A series of CuO‐MnOx‐CeO2/γ‐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/γ‐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/γ‐Al2O3 catalytic particles was maintained at over 80 % within a temperature range of 100–200 °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 · m−3 of SO2, indicating that SO2 and H2O have an inhibiting effect on NOx conversion.

Low-temperature selective catalytic reduction of NO with NH3 over an FeOx/β-MnO2 composite

“…The four main peaks were Fe 3+ (710 eV and 724 eV) and Fe 2+ (712.7 eV and 726.3 eV); the weak peak at 718 eV was probably a satellite peak of Fe 2p 3/2 and the weak peak at 732.7 eV a satellite peak of Fe 2p 1/2 . 60 The binding energies of 710.8 eV and 712.7 eV of Fe 2p 3/2 and 724.2 eV and 726.3 eV of Fe 2p 1/2 were attributed to Fe 3+ . 61 The peak had a certain shift after the introduction of Fe, which may be the reaction of a small amount of Mn 2+ with Fe 3+ in the catalyst.…”