| Formaldehyde is a representative VOCs in air pollutants and leads to adverse health effects to human.It is also identified as a potential human carcinogen,and is an incentive of a variety of diseases.Therefore,development of sorbent-catalyst and viable technology for effective remove of HCHO is the primary objective and task of HCHO control.This paper introduces the physicochemical properties,existing forms,sources and harm of HCHO.It also discusses the research progress of HCHO control technologies.Then,the properties of AC and its application in industry have also been stated.CuO-CeO2 supported on commercial cylindrical activated coke granular(CuCe/AC)were prepared by impregnation method.The effects of Ce/Cu molar ratio in CuO-CeO2,CuO-CeO2 loading value,reaction temperature and flue gas components(O2,NO,SO2)on HCHO removal efficiency were investigated,respectively.Stability test for HCHO removal was also performed.N2 adsorption/desorption,ICP-AES,XRD,SEM,H2-TPR,XPS and FTIR analysis were employed to analyze the characteristics of the sorbent-catalysts.The mechanism of HCHO removal over the sorbent-catalysts combining with the results of characterization analysis and experiment was illuminated.The experimental results showed that the modified AC possessed higher HCHO removal efficiency and better stability than virgin AC,moreover,CuCe/AC performed better than Cu/AC and Ce/AC,which indicated that CuO and CuO have a synergy on HCHO removal.The maximum conversion efficiency(98.7%)of HCHO could be obtained over Cu3Ce8/AC.The effects of flue gas components on HCHO removal were investigated,the presence of NO and SO2 exhibited a slight inhibitive effect on HCHO removal in the presence of 6%O2.The excellent conversion property of Cu3Ce8/AC was related to the high surface area,large pore volume,high dispersion of copper species,good adsorption capacity and great redox ability of metal oxides.Besides,the synergy between Cu and Ce species improved the mobility of activated oxygen species and the content of chemisorption oxygen,which facilitated the conversion of HCHO greatly.XPS and FTIR analysis results revealed that HCHO removal efficiency of Cu3Ce8/AC resulted from the adsorption and catalytic oxidation of HCHO,both lattice oxygen and chemisorption oxygen participated in oxidation reaction.Adsorbed HCHO on the samples surface was oxidized into intermediates,which could be further decomposed into H2O and CO2 by the surface active oxygen of Cu3Ce8/AC.Along with the advantages of Cu3Ce8/AC,it would be a promising material for the removal of HCHO in real industrial application. |
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