Experimental Study Of Diesel Exhaust Depurate Honeycomb Fe-Mo/ZSM-5 Catalyst

Because of the power fuel economy and stability of reliability,Diesel vehicles has a incomparable advantages compared with gasoline engine it is no longer confined to marine and large trucks,but gradually expanded to all mobile vehicles.In the future years,the emission standards with international standards to reach EuropeⅣ.A simple internal Purification is far not enough to meet the increasingly stringent emission requirements.Therefore,organic combination of the internal Purification and exhaust emissions after-treatment become the future solution methods of diesel exhaust emissions.SCR is suited to catalytic removal of NOx from diesel vehicles.Preliminary studies by our group found that Fe-Mo/ZSM-5 catalyst with NH3 as reducing agent in the NOx-SCR reaction has good catalytic activity and a wide temperature window. In order to applied the powder catalyst to the practical.we are coating the powder catalyst to honeycomb cordierite carrier and reviews the effect of preparation methods of catalyst,auxiliary agent,coating methods of carrier to the activity of honeycomb-catalyst.Then design honeycomb catalyst for vehical and carry on intermediate test. This paper draws the following conclusions: (1) The technology used in the project, both of the co-impregnation sample, and vapor ion-exchange samples are able to guarantee its honeycomb catalyst activity the same as the activity of powder samples , individual samples are even increased.(2) Different kinds of honeycomb carrier are also have certainly effects to the activity of catalyst. For the same size of carrier ,we apply the same coating methord.Catalyst made by Corning carrier, the amount of the catalyst coating, catalytic properties, is superior to the Catalyst made by Shanxi carrier.(3) The preparation method of the honeycomb catalyst activity has a significant impact. honeycomb catalyst or powder catalyst samples were prepared by vapor ion-exchange, its catalytic activity was significantly higher than the samples prepared by co-impregnation, and the temperature window is more broader than the total samples prepared by co-impregnation.(4) The powder samples prepared by vapor ion-exchange method adding K+ ions help to improve the low temperature of catalyst activity and high temperature stability.To join the B4+ ions, have resulted in its high-temperature catalytic activity decreased.(5) The level of catalytic activity not only with the category of active component, but also to the load amount of the active component.To same degree,the coating amount of active component greater the higher of the catalytic activity.As the load increases,the catalytic activity reach highest.keeping increasing the amount of active components,the catalytic activity did not significantly improve.(6) Determining the shape of overall catalytic is cylindrical.the shape of the shell is facilitate welding,good stiffness, simple assembly process. Cushioning material is ceramic fiber mat, which can play a good fixation, making ceramic carrier from external shocks and vibrations, while effectively preventing exhaust from the ceramic substrate and the shell in gaps leak.(7) The steady-state conversion efficiency tests show that the catalytic conversion efficiency can basically reach more than 50% at 250℃, conversion efficiency has a wide window. NOx emissions to meet EuropeⅣemissions standards.