Systhesis Of Cu-Based Catalysts And The Study On Their Catalized Properties Of CO Oxidation

As the typical pollutant in the air pollution,CO is derived from industrial production,transport and every involving human life.This seriously affects the human living environment.CO as a probe molecule is often used to study the structure of the catalyst,which occupies an important position in academic research.Therefore,it is of great significance to study the catalytic oxidation of CO.At present,the catalyst used in this reaction is mainly noble metal catalysts and non-noble metal catalysts.Due to its low price,a variety of valence,copper catalyst in the non-noble metals has been widely concerned.In addition,on account of structural diversification,large specific surface area,high porosity,diversity of organic ligand function,a large number of vacant metal sites and many advantages,metal organic skeleton materials?Metal-Organic Frameworks,MOFs?are often used to synthesize metal oxides.At present,the preparation of copper oxide with MOFs as precursors is not clear for the active species,low activity and poor stability in CO oxidation.In this paper,Cu-BTC was used as precursor to prepare Cu_xO catalyst.The active species of CO oxidation on Cu_xO catalyst were well studied by the method of temperature,time and atmosphere.In addition,Cu species were incorporated into Ag/SBA-15,in order to reduce the silver loading to enhance its application,and to study the AgCu bimetallic catalyst in the CO catalytic oxidation of the synergistic effect.1.A series of Cu_xO catalysts were prepared by using Cu-BTC as precursors.Pretreatment factors are temperature and time.The physical and chemical properties of the catalysts were analyzed by XRD,SEM,H₂-TPR and XPS.The results showed that the catalytic activity of Cu-BTC was improved with the increase of pretreatment temperature.The best pretreatment temperature should be 250 ^?.By this time,the complete conversion temperature of CO was only 140 ^?.The study found when the pretreatment temperature reached 250 ^?,the Cu-BTC skeleton structure began to collapse to form Cu species.Characterization analysis shows that the activity of Cu_xO catalyst is related to the proportion of Cu₂O/CuO.With the increase of pretreatment time,the catalytic activity of Cu-BTC samples increased gradually.At this point,the activity of the Cu_xO catalyst is not only related to the proportion of Cu₂O/CuO,but also to the specific surface area of the catalyst.2.A series of Cu_xO catalysts were prepared by using Cu-BTC as precursors.Pretreatment factors is atmosphere.The physical and chemical properties of the catalysts were analyzed by XRD,SEM,H₂-TPR and XPS.When the pretreatment atmosphere are the reaction atmosphere?CO?,the oxidizing atmosphere?O₂?,the reducing atmosphere?H₂?and the inert atmosphere?Ar?.The conversion of CO to CO₂was as follows:CO>O₂>Ar>H₂.Therefore,The activity of copper catalyst is related to the ratio of Cu₂O/CuO in the CO catalytic oxidation reaction.3.The Ag-Cu/SBA-15 catalysts were prepared by impregnation method by adjusting the loading of copper.The pretreatment conditions of Ag-Cu/SBA-15 catalysts were continuously controlled.It was found that the catalyst with no load of copper exhibited the best catalytic activity after treatment with oxygen?500 ^??.However,the catalytic activity of the catalyst was improved in different degrees after treatment with hydrogen?300 ^??.And the activity of Ag?1?-Cu?0.025?/SBA-15 catalyst is better than that of Ag/SBA-15 catalyst.The activity of these two catalysts after pretreatment with hydrogen at different temperatures was also investigated.The results show that the activity of Ag?1?-Cu?0.025?/SBA-15 catalyst is still better than Ag/SBA-15 catalyst.And for both catalysts,hydrogen?300 ^??is the optimum pretreatment temperature.At this time,there is a synergistic effect between silver and copper bimetallic,and the active species of silver is Ag⁰.