Study on the effect of Ce-Cu doping on Mn/γ-Al₂O₃ catalyst for selective catalytic reduction in NO with NH₃

A series of Mn/γ-Al₂O₃, Mn-Cu/γ-Al₂O₃, Mn-Ce/γ-Al₂O₃ and Mn-Ce-Cu/γ-Al₂O₃ catalysts were prepared by equal volume impregnation. The denitrification effects of the different catalysts were studied by activity measurement, X-ray diffraction, Brunauer, Emmett, and Teller surface area tests, Scanning electron microscopy, H₂-temperature programmed reduction and Fourier-transform infrared spectroscopy. The experimental results show that Ce and Cu are added to a Mn/γ-Al₂O₃ catalyst as bimetallic additives, which weakens the interaction between Mn and the carrier, improves the dispersion of MnO_x on the surface of the carrier, improves the specific surface area of the catalyst, and improves the reducibility. Mn-Ce-Cu/γ-Al₂O₃ catalyst reaches a maximum conversion of 92% at 202 °C. Also, the addition of the auxiliary metals promotes the reaction mechanism to a certain extent, and the addition of Ce especially promotes the conversion of NO-NO₂, which is conducive to the production of intermediate products that promote the NH₃-SCR reaction.