Preparation,Characterization And Property Of Catalytic NO Reduction By CO Of CuO/MnO_x And Cu/TiO₂

It is one of the hot topics for researchers to find a kind of nonprecious metal catalyst with low cost,Earth-abundance,environmentally benign and high catalytic activity to replace precious metal catalysts for NO abatement.So far,researchers have studied many nonprecious metal catalysts including metal oxides and their nanocomposites,and they found that CuO have good catalytic activity.Copper oxides supported on various oxides have also been extensively studied by researchers.However,most of the catalysts prepared have the disadvantage of poor catalytic cativity activity at low temperature.This paper deeply researched the preparation,characterization and catalytic activity of nanocomposites that have excellent catalytic performance.On the other hand,this paper also studied the effect of different reduction methods on the catalytic activity of nanocomposites and the reason for catalytic activity difference.The main research results are as follows:1.With KMnO₄,Mn?NO₃?₂ and Cu?NO₃?₂ as raw materials,CuO/OMS-2nanocomposites with different molar ratios of Cu/Mn were prepared by hydrothermal method and impregnation method.The catalytic activity and stability of CuO/OMS-2catalysts with different Cu/Mn molar ratios were studied.After comparison with the commodity catalysts,the T₅₀ and T₉₀?NO conversion ratio of 50%and 90%of NO conversion?of the CuO/OMS-2 catalysts decreased significantly compared with the commodity catalysts.By analyzing the results of TPR,XRD,TEM and XPS characterization,we found the reaction mechanism that how CuO/OMS-2 nanometer compound catalytic NO reduction by CO.In addition,the interfacial interaction between the metal Cu and Mn3O4 is found to be a key factory for raising the catalytic activity of CuO/OMS-2 nanometer compound.2.With TBOT and Cu?NO₃?₂ as raw materials,CuO/TiO₂ nanocomposites were prepared by hydrothermal method and impregnation method.Cu/TiO₂ nanocomposites were prepared by two methods of reduction of CuO/TiO₂ nanocomposites were reduced by CO and NaBH4,respectively,to obtained Cu/TiO2 nanocomposite?denoted as Cu/TiO₂-CO and Cu/TiO₂-NaBH₄,repectively?.Through the catalytic activity test,Cu/TiO2-NaBH4 nanometer complex was found to have better catalytic activity and stability than Cu/TiO2-CO nanocomposites.With the characterization of NO-TPD and CO-TPD,we found that Cu/TiO2-NaBH4 has more CO weak chemical adsorption,thus increasing the catalytic activity of the sample.In addition,the results of XRD show that Cu/TiO2-NaBH4 has a smaller grain size,which results in greater activity ratio and further improvement of its catalytic activity.