MnOx/CeO2 catalysts for the low-temperature selective catalytic reduction of NO with NH3

Abstract

CeO2–nanorod support was synthesized by hydrothermal method and different manganese oxides (MnO, MnO2, and Mn2O3) were impregnated over support by the wet-impregnation forming MnO/CeO2-NR, MnO2/CeO2-NRm and Mn2O3/CeO2-NR. The physico-chemical properties of the as-prepared catalysts were analyzed using x-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area, x-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscope–energy-dispersive x-ray spectroscopy (SEM–EDX), hydrogen-temperature-programmed reduction (H2-TPR), and Raman spectroscopy. These catalysts were further analyzed for NO reduction using NH3 as a reducing gas in the temperature range of 50 to 450°C. The results confirmed that MnO2/CeO2-NR gave the maximum NO conversion (65%) and N2 selectivity (89%) among all catalysts. Further, MnO2/CeO2-NR catalyst was studied for the effect of MnO2 loading and more than 90% NO conversion and N2 selectivity were obtained in the temperature range of 250 to 300°C. © 2023 Canadian Society for Chemical Engineering.