Study On The Influence Mechanism Of Nickel And Cerium Doped Activated Carbon With Copper-containing Catalyst On Low Temperature CO-SCR Denitration Performance

Low-temperature selective catalytic reduction(CO-SCR)nitrogen oxide technology using CO as a reducing agent is currently one of the research hotspots in the field of low-temperature denitrification of sintering flue gas in iron and steel enterprises.CO-SCR denitration technology has the advantages of long catalyst life,not easy to produce solid salts to block the pores,and capable of simultaneously removing CO and NOx polluting gases.For CO-SCR low-temperature denitrification technology,the development of catalysts has become the key to determining denitrification performance.As a catalyst carrier,coconut shell activated carbon(AC)has a huge specific surface area and developed pore structure.It also has the advantages of high adsorption capacity,high mechanical strength,and stable physical and chemical properties.It has become a commonly used adsorption material and catalyst carrier for flue gas purification.In this paper,the activated coconut shell activated carbon by air thermal oxidation and nitric acid activation is used as the carrier,and Cu/AC is prepared by loading copper nitrate,and then Cu/AC is doped with Ni and Ce metal oxides to prepare Cu-Ni/AC and Cu-Ni-Ce/AC achieve the purpose of improving the denitration performance of low-temperature CO-SCR.At the same time,SEM,BET,FTIR,XRD,XPS,CO-TPD,NO-TPD were used to characterize the physical and chemical properties of the prepared catalyst,and to study the effect of the synergy between metal oxides on the denitration performance.The main research contents are as follows:A catalyst with Cu₂O as the active ingredient was prepared from AC activated by air thermal oxidation.It was found that the Cu on the Cu/AC catalyst was in the form of spherical Cu₂O that was uniformly dispersed on the surface of the AC pores and had better crystallization performance.Increased the active sites in contact with the reaction gas CO and NO_X to promote the rapid progress of the CO-SCR reaction.From the characterization results,it can be found that as the load increases,the specific surface area,the number of micropores,and the type and number of functional groups will show an increasing trend.The Cu-Ni/AC catalyst was prepared by Ni-doped Cu₂O/AC,and it was found that the co-support of copper and nickel made the Cu-Ni/AC catalyst reduce the loss of specific surface area during the calcination process.And a single split it into smaller,irregular graphene fragments.The redox reaction between copper and nickel metal oxides leads to an increase in the amount of adsorbed oxygen(O?)on the surface,which promotes and adsorbs more reaction gases(CO,O₂,NO),resulting in the conversion of standard SCR reaction to fast SCR reaction.Investigating the effect of activation method and Ce doping amount on Cu-Ni/AC catalyst,it is found that although the specific surface area of AC activated by nitric acid is slightly lower than AC activated by air thermal oxidation,the pore structure of AC activated by nitric acid is more developed The number of oxygen-containing functional groups has increased significantly.Through Ce doping,a uniformly dispersed Cu and Ni metal oxides can be obtained.The Cu and Ni metal ions on the Cu-Ni-Ce/AC_0,1 catalyst both increase the average valence state and the adsorbed oxygen content on the surface,and absorb more CO,NO reaction gas.Through the oxidation-reduction reaction between metals,the introduced O₂ is converted into(O?),which promotes the conversion of NO into NO₂,and accelerates the progress of the CO-SCR reaction.