Preparation Of Fe And Mn Containing Rare Earth Based Nano-Catalysts That Is Appilcated To Purification Of Automotive Exhaust

Recently, with the cut-throat competition on the automobile market in our country and the high-speed growth in number of car, exhaust pollution of motor vehicle that has been incriminated as one of the causes of air pollution in cities became worse, which has caused wide public concern and highly valued. At present, the essential technique of exhaust pollution control is to use the system of electronic fuel injection and three way catalyst converter together in the international market. As the core part of the technique, three way catalyst converter plays an important role in the exhaust pollution control. In abroad, three way catalyst using in car has already realized commercialization. And precious metal three way catalyst that is composed of Pt, Pd and Rh have very high efficiency of transformation for the efficiency of transformation the poisonous gas of CO, NO_x and HC. but they have some shortcomings: lacking of resources, expensive price, high cost and secondary pollution and so on. Meanwhile, our country flows extremely with rare earth resources. Studies show that the metallic element of the rare earth that have special catalyst function and property thus are very lively and can form stable compounds with a number of chemical element. To join rare earth into precious metal catalyst will raise the mithridatism, thermal stability and catalytic activity of catalyst consumedly. At present, the nanometer material get extensive research and approving as the fourth generation catalyst of exhaust in the world. The use of nanometer technology prepares some catalysts, which can make the compound having been preprared express some special physical effects and show special effects that other material can't realize. Therefore, some new and efficient catalysts with self-developed hi-tech products are crucial to reduce the cost of catalyst, make a more comprehensive use of rare earth resources and control atmospheric pollution in our country.Using the oxides of rare-earth elements(La₂O₃, Ce₂(CO₃)₃), Fe(NO₃)₃·9H₂O and Mn(NO₃)₂(AR, 50%) as raw material, the aerogel of RE₂O₃-Fe-Mn was prepared by sol-gel and vacuum drying technology to obtain nanometer powder and the samples were characterizated by means of FT-IR, XRD, TEM and TG-DTA. The key aim was to examine the effect of preparation methodology and temperature on crystalline state, appearance and size, systematically carried on a comparison to the catalyst function of the catalyst of LaMnO_3+λ, CeMnO_3+λ, La_0.5Ce_0.5MnO_3+λ, LaFe_0.5Mn_0.5O_3+λ, CeFe_0.5Mn_0.5O_3+λ and La1-xCexFe_0.5Mn_0.5O_3+λ(x=0.3, _0.5, 0.7), and analyzed the influence on catalytic performance by the replaces and blending in the perovskite structure of A and B , the proportion of blending and the different temperature of calcining. then through"NO+CO"reaction to check its catalytic activity , study on the stability of catalysts and inquiry into the catalyst mechanism, which anticipate to find out the catalyst of having the best catalytic activity.