Low-temperature selective catalytic reduction of NOx with NH3 over a manganese and cerium oxide/graphene composite prepared by a hydrothermal method

MnOx-CeO2/graphene (MnOx-CeO2/GR) catalysts prepared by a hydrothermal method with different mass ratios of graphene (0-0.45 wt%) were investigated for the low-temperature selective catalytic reduction (SCR) of NOx with NH3. The as-prepared catalysts have been characterized systematically to elucidate their morphological structure and surface properties by XRD, SEM, TEM, BET, XPS, H-2-TPR, NH3-TPD and FT-TR. It was found that the environmentally benign MnOx-CeO2/GR (0.3 wt%) catalyst exhibited excellent NH3-SCR activity and strong resistance against H2O and SO2, which is very competitive for application in controlling NOx emission from flue gas. On the basis of the catalyst characterization, the high specific surface areas, the uniform distribution of active sites, and the interaction of manganese and cerium oxide species played key roles in the excellent catalytic performance of MnOx-CeO2/GR and resulted in improved SO2 tolerance.