Cu-Ni/AC Catalyst for Low-Temperature CO-Selective Catalytic Denitration Mechanism

To study the preparation principle of Cu-Ni/AC catalysts and the mechanism of low-temperature CO-selective catalytic reduction (SCR) denitration, Cu-Ni/AC catalysts with different metal loadings were prepared by the isometric ultrasonic impregnation method. It was determined that the 10Cu-4Ni/AC catalyst had the best CO-SCR low-temperature denitration rate of 94.2% in 5% O-2 and at the denitration temperature of 150 degrees C. The characterization of Cu-Ni/AC by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and CO temperature-programmed desorption (TPD) confirmed that the copper-nickel-coordinated loading resulted in the Cu-Ni/AC catalyst having a rich pore structure and a large number of acidic oxygen-containing functional groups. The spherical particles of copper-nickel oxide with good thermal stability were highly dispersed on the AC surface, allowing the copper and nickel metal ions to enter the graphite or graphite-like microcrystalline structure and split into smaller irregular graphene fragments, thus forming a large number of denitration reaction units on the AC surface. The oxidation-reduction reaction (Cu2+ + Ni2+ + Cu+ + Ni3+) between copper and nickel metal oxides produced active oxygen vacancies, which increased the amount of oxygen (Oa) adsorbed on the surface, especially acidic adsorption sites on the surface; this promoted the higher adsorption of reaction gases (CO, O-2, NO), leading to the conversion of a standard SCR reaction to a fast SCR reaction, which, in turn, improved the denitration efficiency. The CO-SCR denitrification mechanism model of the Cu-Ni/AC catalyst was discovered and established according to the experimental results and theoretical analysis. The related research provides a reference for carbon-based catalysts for low-temperature CO-SCR denitration.