Study On The Preparation And Denitration Performance Of Cerium Titanium Catalysts For Catalytic Ozonation

Nitrogen oxide(NO_x)is one of the main atmospheric pollutants,but some small and medium devices such as industrial furnaces,sintering machine and catalytic cracking unit boiler exhaust smoke temperature is low,which is not suitable for installation of selective catalytic reduction(SCR)of denitration device temperature(320?400?).Catalytic ozonation denitration technology is a kind of suit denitration technology,and which is put forward on the basis of ozone treatment process.To promote the process of industrialization,this paper is focused on catalyst preparation,modification and denitration performance research,explores the mechanism of reaction process based on the catalytic ozonation denitration technology,and then the industrial catalyst was prepared for the actual flue gas denitration performance testing and debugging process.First of all,we select Ce as the active ingredient of the catalyst,Mn doping Mn-Ce solid solution formed by a percentage of and then load on the titanium dioxide carrier preparation got Mn-Ce/TiO2 catalysts as the research object,investigates the influence of the different synthesis methods and the carrier with different crystalline phases on catalyst for catalytic activity.It has been found that anatase and monoclinic mixed-phase of the carrier of the catalyst has the highest activity,the denitration activity can amount to 90%at 40 ?.We explored the reaction mechanism of catalytic ozonation denitration,found in the catalytic ozonation denitration,hydroxyl free radical were the main active material,oxygen vacancy on the surface of the catalyst is beneficial to the formation of surface hydroxyl,ozone can with surface hydroxyl function to generate hydroxyl free radicals and denitration reaction.Through the characterization of blended found anatase and monoclinic crystal phase of titanium dioxide vector corresponds to the surface of the catalyst has more oxygen vacancy and the surface hydroxyl number,and the surface hydroxyl activity is higher,and therefore has good catalytic activity.But in the catalytic ozonation denitration industrial applications,complex catalyst preparation,the success rate is not high,conducive to the practical industrial application,need further improvement.For this purpose,the amorphous CeTi composite oxide catalyst was prepared with coprecipitation method,and uses the fluorine doping for it.Fluorine doping promote the interaction between the Ce and Ti,fluorine atoms replace oxygen atoms in the crystal lattice,and the surface oxygen vacancies and the surface hydroxyl number increased on the catalyst surface,and to make catalyst surface hydrophilicity stronger,easier to form the surface hydroxyl,thus enhance denitration catalyst efficiency.Compare Mn-Ce/TiO2 catalysts,CeTi catalyst also showed good catalytic activity but the preparation process is more simple.It is suitable for industry production,and this is a kind of catalytic ozonation denitration catalysts for industrial applications.According to certain ratio of Ce and Ti to prepare granular CeTi catalyst,joined the ozone generator on flue gas pipeline and high pressure spray etc.catalytic ozonation denitration process equipment.The catalysts was tested under the conditions of coal-fired boiler flue gas,and optimize some of process conditions,we have found that the catalytic ozonation denitration techonology has a certain extent effect,but still have certain disparity away from the laboratory results,it is needed to make some effort on the optimization of catalyst molding and technological parameter.We have accumulated certain experience on the preparation of catalyst molding and process conditions,and also laid the foundation of developing more suitable industry catalyst for catalytic ozonation denitration.