Selective catalytic reduction of NO(x) by low-temperature NH(3) over Mn(x)Zr(1) mixed-oxide catalysts

Mn(x)Zr(1) series catalysts were prepared by a coprecipitation method. The effect of zirconium doping on the NH(3)-SCR performance of the MnO(x) catalyst was studied, and the influence of the calcination temperature on the catalyst activity was explored. The results showed that the Mn(6)Zr(1) catalyst exhibited good NH(3)-SCR activity when calcined at 400 °C. When the reaction temperature was 125–250 °C, the NO(x) conversion rate of Mn(6)Zr(1) catalyst reached more than 90%, and the optimal conversion efficiency reached 97%. In addition, the Mn(6)Zr(1) catalyst showed excellent SO(2) and H(2)O resistance at the optimum reaction temperature. Meanwhile, the catalysts were characterized. The results showed that the morphology of the MnO(x) catalyst was significantly changed, whereby as the proportion of Mn(4+) and O(α) species increased, the physical properties of the catalyst were improved. In addition, both Lewis acid sites and Brønsted acid sites existed in the Mn(6)Zr(1) catalyst, which reduced the reduction temperature of the catalyst. In summary, zirconium doping successfully improved the NH(3)-SCR performance of MnO(x).