| With the fast development of the human society and more and more energy consumed by vehicles, the exhaust gas pollutions from vehicles are becoming more and more serious for the living environment and human health. CxHy exhaust pollutants from diesel vehicles have more than 200 kinds. They can irritate and hurt human eyes and noses. CxHy can also involve in photochemical reaction to produce secondary pollutants which can hurt the human body function and destroy plant tissue. Nitrogen oxides are one kind of gaseous pollutants that contribute to the acid rain formation, the photochemical air pollution, and the depletion of the ozone layer.90% of the substances adsorbed on the PM are carcinogenic. These harmful substances can also lead to chronic lung disease. In order to protect our living environment, the strict emission control regulations for diesel vehicles have been constituted in USA, Japan, and many Europe countries. Now, green living environment was advocated more and more. This could make a higher demand on the selecting and the performance of catalysts. In this paper, we select alloy and CuCr2O4 CoCr2O4 as the support and catalysts. Glass ceramic coating was used to improve the dispersion of the catalyst and the adherence between the catalyst and the support.In this thesis, glass-ceramic coating was coated on metal support as the second-support. Highly catalytic activity catalysts CuCr2O4 CoCr2O4 were deposited on glass-ceramic coating to prepare diesel catalytic converter with excellent performance. The spinal type oxides have been widely used as active catalysts for the removal of pollutants from automobile exhaust because of their longer life, lower combustion temperature.There has been intense interest in the metal support due to their advantages of good thermal conduction and stability, high ductility and mechanical intensity. The support is widely used on fuel-battery, thermal converter, catalytic converter; however, surface area of metal support is quite small, needed to cover porous materials such as Al2O3 glass-ceramic-coating to enlarge the surface area when used. But thermal expand coefficient of metal is different from the one of coating, which leads to bad mechanical intensity, and this disadvantage limit application of metal support in practice. In this research, we put SiO2 to traditional Al2O3 glass-ceramic-coating, which could solve this problem.This thesis involves the pre-prepared method about the NiCrFe alloy metal support, glass-ceramic-coating, and four-way-catalyst of price and non-price metal, which limit PM, NOx, CO, and CxHy. Oxides the metal support at different high temperature before pre-prepared method with acid and alkali corruption. Then analyzing the surface form based on SEM to decide the best preparing temperature. Glass-ceramic-coating prepared with sol-gel method at the surface of NiCrFe alloy metal support could provide good adherence intensity between support and catalyst by XRD, BET and SEM tests. Ultrasonic vibration test, thermal impulse and stretch test could identify the best molar ratio of coating components which gives wonderful adherence intensity with support. We prepared price catalysts (Pt, Pd) and non-price catalysts (CuCr2O4,CoCr2O4, and Co1-xCexCr2O4 (x=0.05,0.1,0.15)) and tested them in the lab and practice conditions, and testify non-price catalyst Co1-xCexCr2O4 (x=0.1时) give the best conversion and selectivity to PM and NOx.The research of choice of support and surface disposal are based on some different alloy metal support such as FeCrAl,NiCrFe,NiCr, we treat them with different techniques and test them for SEM, XRD, and BET, analyzing their forms and properties. Different techniques of metal support disposal could impact the forms and properties of metal support. Alkali disposal could reduce support surface dirt, while acid disposal may erode surface which could form a piece of uniform oxide coating, increase adherence intensity between support and coating. The best condition of calcining NiCrFe is at 900℃for 5h.Al(NO3)3·9H2O and TEOS as raw materials, we choose sol-gel method to prepare glass-ceramic-coating with different molar ratio of Si and Al at alloy metal support. Different preparation condition could impact the forms, crystalline and adherence intensity. We compared this coating with traditional coating by XRD. SEM. thermal impulse, ultrasonic vibration test, and stretch test and find that this coating could provide larger surface area, enhance adherence intensity between SCR system and catalyst, furthermore the calcine temperature is low and preparation method is relatively simple. Based on our research, the best molar ratio of amorphous glass-ceramic-coating is 5 to 1. Under FT-IR and XRD test we can prove that SiO2 could restrain the crystal of Al2O3, making compound coating stable. Based on BET test and adsorb and desorbed curves prove that the coating with molar ratio 5 to 1 provide largest surface area, small pore radius.Among many catalysts at SCR reaction, spinel type oxidation catalyst is one of the best catalysts. We use citric acid method to prepare CuCr2O4 CoCr2O4 and Co1-xCexCr2O4 (x=0.05,0.1,0.15) catalysts, then test their activity and form by XRD, SEM. gas chromatography. The results show that no other crystalline appears, and this kind of catalyst could reduce PM and NOx at the same time. During lab experiments, the activity of CoCr2O4 is better than that of CuCr2O4. Ce modified CoCr2O4 could increase the activity. x=0.1mol is the best recipe.The catalyst was deposited over the metal support to prepare the catalytic converter. The catalytic converter was tested on real exhaust gases on an engine bench (CA6DL2-35E3). And the experiment result was just satisfied. This kind of catalyst can remove CO, CxHv, NOx and PM simultaneously.
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