共查询到20条相似文献,搜索用时 46 毫秒
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Lü Zhenjian 《中国稀土学报(英文版)》2004,22(Z1)
Diesel soot is related to incomplete fuel oxidation, and possesses the well-known mutagenic effects on human health.Diesel soot was collected from diesel engines and oxidized in laboratorial micro reactor by several prepared rare earth-based catalysts with or without different harmful monoxide gases such as NO, and activities of several rare earth catalysts were studied.The results indicate that soot can be more easily oxidized with monoxide gases. 相似文献
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The catalysts of CeO2 and the mixture of CeO2 and CuO were prepared, and the activities of these catalysts for completely oxidizing benzene were studied.The results show that the optimal proportion of CeO2/CuO is 6: 4.The highest temperature at which benzene was completely oxidized on these catalysts at different airspeed was measured.Compared these catalysts with the noble metal used, our catalysts had superiority in the resources and the industrial cost besides good activities. 相似文献
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Catalytic performances of a series Ce/Zr oxides(CexZr1-xO2 )for soot combustion were investigated. The catalytic activities for soot combustion were affected by both the Ce/Zr ratio and the oxygen storageinvestigated. Thecapability of Ce/Zr oxides. O2-TPD and TG-DTA results indicate that CexZr1-xO2 can release its lattice oxygen continuously and promote soot combustion even no oxygen occurs in the reaction atmosphere. Among these Ce/Zr oxides, Ce0.5Zr0.5O2 has the best catalytic activity, and the ignition temperature of soot combustion was about 410℃, which is close to the practical exhaust temperature of the diesel engine. 相似文献
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A new catalyst system was used in the synthesis of polyethylene terephthalate(PET) and its copolymers, which involved a Ln3 containing compound. The catalytic effects were studied, and it was found that the direct esterification reaction of terephthalate acid(TPA) with ethylene glycol (EG) can be accelerated by the addition of Ln3 ~ containing compound, which acts as a promoter of the catalyst Sb203 in polycondensation of bis hydroxyethyl terephthalate(BHET). 相似文献
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Development of Auto Exhaust Catalysts and Associated Application of Rare Earths in China 总被引:1,自引:0,他引:1
There are at least three obvious trends in the developments of automotive market in China : the evolution of emission standards from Euro Ⅱ to Euro Ⅲ, the demand of lean-burn gasoline engine and the time of diesel vehicles. The latest application and advances of exhaust catalysts by Chinese researchers, using some high effcient,economical and durable methods to meet these changes in emission regulations laws and engine technologies, were described. Rare earth oxides, such as lanthana, ceria-based solid solutions and perovskite-type oxides, are widely used as excellent promoters for thermal stability,oxygen storage capacity and oxidation/reduction activity in these catalysts. Four phases in the development of the auto exhaust catalyst industry in China since the mid 1970s were reviewed. It is argued that China will become the center of global auto exhaust catalysts industry in the next decades with its economic, technical and environmental incentives,which greatly depends on the research and development of rare earth. 相似文献
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Zhu Ling Wang Xuezhong Liang Cunzhen 《中国稀土学报(英文版)》2006,24(5):528-528
The K2NiF4 type oxides, La2-x KxCuO4 complex oxides with nanometric size were prepared by sol-gel method. The characters of these samples were analyzed by H2-TPR, XRD, FT-IR and SEM. The catalytic activity for soot combustion was evaluated by temperature-programmed reaction (TPO) technique. The results demonstrate that the substitution of K^+ for La^3+ at A-site will increase the catalytic activities of La2-xKxCuO4 to soot combustion greatly, and the substitution quantity affects the structure and catalytic activity obviously. The La1.8 K0.2 CuO4 complex oxides with tetrahedral structure has the best catalytic activity for soot removal reaction, the ignition temperature of soot combustion is decreased from 490 to 320℃. 相似文献
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A series of catalysts were prepared by using complex sol-gel methods.Experimental results confirm the effect of different agents on structure and activity of Fe-substituted rare earth hexaaluminate catalyst (LaFeAl11 O19 ) for methane combustion.The catalyst is yielded by complex sol-gel, respectively using three different complex agents (maltose, glucose and citric acid).XRD demonstrated that haxaaluminate is the major phase of catalyst prepared by maltose,while LaAlO3 is the major one of the catalyst by glucose and citric acid.At the same time, there is a little LaFeO3 and surface areas as well as 29.5 nm particle diameter when the complex agent is maltose.However, T10 ( temperature for 10% conversion of methane) and T100 ( temperature for 100% conversion of methane) for catalyst by glucose is 543 and 758 ℃, which is the best among the three complex agents for methane combustion. 相似文献
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Li Fenping Liang Jinsheng Zhu Dongbin Ding Yan Wang Lijuan Liang Guangchuan Wang Yanan 《中国稀土学报(英文版)》2006,24(Z2)
The rare earth composite ceramic materials were prepared using rare earths and far infrared natural mineral. The effects of the as-prepared ceramic materials on the oil consumption and air pollutants emissions of oil-burning boiler were investigated. The results show that the composite ceramic materials can radiate higher intensity of far infrared. The molecular movement is strengthened and the chemical bonds of the molecules are easily ruptured when the diesel oil is dealt with the composite materials. The oil-saving rate of the RBS·VH-1.5 boiler dealt with the rare earth composite ceramic materials is 3.49%, and the reducing rates of CO and NO in the exhaust gas are 25.4% and 9.7%, respectively. 相似文献
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Migaku Kobayashi Ryoko Katsuraya Tsubasa Nara Yusuke Tomita Hiromi Nakano Naoki Kamegashira 《中国稀土学报(英文版)》2006,24(6):668-672
Several compounds of rare earth complex oxides containing manganese and titanium were synthesized in Ar, and their crystal structures were analyzed by powder X-ray diffraction data and Rietveld method. Structures of A0.67Ln0.33 Mn0.33Ti0.6703(A = Ca or Sr and Ln = rare earth) were found to have orthorhombic symmetry with the space group Pnrna, and their interatomic distances and bond angles were obtained. This space group was also derived from electron microscopic study. Electrical conductivity of Cao.67Ln0.33Mn0.33Ti0.6703 for several rare earth elements showed a semiconducting property with the activation energy of 0.4 eV. Some of these compounds of the strontium system show the antiferromagnetic properties below 10 K. 相似文献