As a common heavy metal in the sintering flue gas,Pb can exist in the form of oxide(PbO)and lead to the decrease in the denitration catalysts activity.Ce-Mn/AC(activated carbon)and PbO-Ce-Mn/AC catalysts were prepared by impregnation method and their selective catalytic reduction of NH3 with NO was studied.Results showed that selective catalytic reduction activity of Ce-Mn/AC decreased remarkably after doping PbO.And the NO conversion of Ce-Mn/AC reached 94.52%at 200 ℃,while the value was reduced to 65.8%after doping PbO at the same temperature.The doping of PbO decreased the total pore volume and oxygen functional groups of activated carbon,increased crystallinity of Mn oxides on the catalyst,decreased Mn4+and chemisorbed oxygen content and then inhibited the"fast selective catalytic reduction"denitration reac-tion for Ce-Mn/AC catalysts.On this basis,the poisoning effects of lead oxide on Ce-Mn/AC catalysts for low-temperature selective catalytic reduction were revealed.