Influencing factors on low-temperature deNO_x performance of Mn-La-Ce-Ni-O_x/P84

A Mn-La-Ce-Ni-O_x/P84 catalytic filter was prepared by the loading of a P84 filter on n(Mn) ∶n(La) ∶n(Ce) ∶n(Ni) (2.5 ∶2.5 ∶1 ∶1 molar ratio of Mn-La-Ce-Ni-Ox) via an impregnation method, followed by calcining at 550℃. The effect of catalyst loading, reaction temperature, O₂ concentration, NH₃/NO molar ratio, and SO₂ on the low temperature catalytic performance of Mn-La-Ce-Ni-O_x/P84 for the NH₃-selective catalytic reduction (SCR) of NO was investigated. Mn-La-Ce-Ni-O_x/P84 exhibited a high de-NO_x efficiency at 100 to 200℃ with a catalyst loading of >250 g·m^-2. Furthermore, the de-NO_x efficiency increased with increasing NH₃/NO molar ratio and increasing O₂ concentration at NH₃/NO ≤1.0 and O₂ concentration ≤6%, although it remained constant at NH₃/NO >1.0 and O₂ concentration >6%. Finally, the de-NO_x efficiency of Mn-La-Ce-Ni-O_x/P84 decreased to 88.6% in the presence of 300 ppm SO₂ at 200℃ and could not be recovered to its original level following removal of the SO₂.