Prepared Of Honeycomb CuO SCR Catalysts And Research On Denitration Performance

NO_xhas become one of the main air pollutants. It can not only cause acid rain,photochemical smog and ozone layer depletion, but also cause damage to people’shealth. So, it has become a focus on researching how to control NO_xemissionsefficiently. Selective catalytic reduction （SCR） is the most widely used deNO_xtechnology and works best. Choosing a suitable catalyst is the most important part ofSCR. But high costs, easily jammed and short life problems are existing in thepractical applications of current catalysts. So, it is a great significance of researchingand developing a high performance catalyst.It is used BET, SEM, and XRD characterization methods to analyze thecharacteristics of sol-gel γ-Al₂O₃, precipitation γ-Al₂O₃and purchased γ-Al₂O₃. Theresults shows that the size order of γ-Al₂O₃specific surface area is: purchasedγ-Al₂O₃>sol-gel γ-Al₂O₃>precipitation γ-Al₂O₃. After XRD and BET test, it is thoughtthat the best performance γ-Al₂O₃is purchased, the sol-gel method γ-Al₂O₃is better,the worst method is precipitation. But it is difficult to coating γ-Al₂O₃on the surface ofhoneycomb ceramics. Finally, the sol-gel method is chosen to prepare γ-Al₂O₃coating,then the honeycomb CuO catalysts are prepared.The active component CuO was loaded on the surface of γ-Al₂O₃through byimpregnation method. It is researched the influence of CuO loading amount, calciningtemperature and adding promoter Ce preparing factors on the surface properties ofcatalysts. Using SEM and XRD characterization to investigate the microstructurecharacteristics and phase compositions of catalysts in different calciningtemperature（350℃,500℃,650℃a nd800℃） and different loading amount ofCuO（2.5%,5%,7.5%,10%）.The results show that particles of the catalysts loaded5%and7.5%CuO are uniform and the crystal structure is obvious. It is seen that thesurface of catalysts calcined in800℃has been sintered. Catalysts calcined in500℃ are better than catalysts in other calcined temperature. When Ce is added in catalyst, itshows that the Cu/Ce proportion of best structure catalysts is1:0.25.Finally, the denitration efficiency of catalysts is tested. It is researched theinfluence of CuO loading amount, calcining temperature and adding promoter Cepreparing conditions on the denitration efficiency. The experiment results show thatthe highest denitration effect catalysts are7.5%loading amount CuO catalysts. Whenthe reaction temperature is350℃, the highest denitration effect can reach to91.4%.The catalysts calcining in500℃has the highest denitration effect, then is calcining in350℃,650℃,800℃. Denitration effect of catalysts can improve to94.5%when Cewas added. But improvement of catalysts denitration effect is not obvious by added Ce.The denitration efficiency is also affected by reaction temperature. When thetemperature is around350℃, the denitration efficiency of all catalysts can reach to85%. When the temperature is not in the temperature range, the denitration efficiencywould decrease rapidly.