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Effect of cerium on High-Temperature Oxidation Resistance of 00Cr17NbTi Ferritic Stainless Steel

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Acta Metallurgica Sinica(English Letters) 2014年第3期27卷 501-507页

作者： Xin Li Jun Shu Liqing Chen Hongyun Bi State Key Laboratory of Rolling and Automation Northeastern University Research Institute of Baosteel State Key Laboratory of Development and Application Technology of Automobile SteelsBaosteel Group Technical Center Faurecia Exhaust Control Technology Development (Shanghai) Co. Ltd

The influence of cerium addition on the isothermal oxidation behavior of 00Cr17NbTi ferritic stainless steel was studied at temperature up to 1,000 ℃ for 100 h in air. The results show that cerium additions can reduce the grain size of this ferritic stainless steel, improve the diffusion of chromium and decrease the critical concentration of chromium to form protective Cr2O3 layer. With the increasing of cerium addition, the oxide particles become smaller and this can increase the rupture strength and spalling resistance of oxide layers. The transport mechanism through the oxide layer is varied from metal transport outward from steel to principally oxygen transport inward with the increase of cerium content, which leads to the lower oxidation rate and the better scale adherence of 00Cr17NbTi ferritic stainless steel.

关键词： Ferritic stainless steel Oxidation cerium oxides Cavity

La-Hexaaluminate Catalyst Preparation and Its Performance for Methane Catalytic Combustion

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Journal of Rare Earths 2006年第6期24卷 690-694页

作者：崔梅生王良士赵娜龙志奇李殿卿陈霭璠 General Research Institute for Nonferrous Metals Grirem Advanced Materials Co. Ltd. Beijing 100088China Beijing University of Chemical Technology Chemical Engineering Resource State Key Laboratory Beijing 100029China

The La-hexaaluminate catalysts with high performance ration method with the buffer solution of NH4HCO3 and NH4OH were synthesized by the modified controllable co-precipimixture as the precipitation agent. The physicochemical properties of catalysts were characterized by the means of BET, XRD, and TPR techniques. With methane catalytic combustion as the probe reaction, the catalytic performances were also tested on a fixed bed, continual flow system. The resuits show that it is a good method to obtain chemical homogeneous hexaaluminate materials by the buffer solution as the precipitation agent. The La-hexaaluminate can be formed at low temperatures ranging from 1050 to 1200 ℃. The cerium introduction plays a great role in the methane catalytic combustion on La-Mn hexaaluminate because of its high oxygen storage capacity property and the well synergic effect between Ce and Mn. However, the CeO2 appears in hexaaluminate through the XRD pattern, which reveals that Ce can not enter the crystal lattice position. Mn introduction improves the methane catalytic activity to a large extent due to its high redox property. When Mn atomic substitution amount for A1 is 2, the hexaaluminate shows the highest activity, and the catalyst possesses good H2 consumption and redox performance. Mn can easily occupy the hexaaluminate crystal position, which reveals that the Mn substitute La-hexaaluminate is a promising high temperature methane combustion catalyst with high activity and good stability.

关键词： La-hexaaluminate methane combustion cerium oxides rare earths

Low temperature selective catalytic reduction of NO by C_3H_6 over Ce O_x loaded on AC treated by HNO_3

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Journal of Rare Earths 2015年第4期33卷 371-381页

作者：楚英豪张腾腾郭家秀刘超尹华强朱晓帆刘勇军 College of Architecture and Environment Sichuan University National Engineering Technology Research Center for Flue Gas Desulfurization Sichuan University Sichuan Provincial Environmental Protection & Environmental Catalytic Materials Engineering Technology Center Sichuan University

The activated carbons from coal were treated by HNO3 （named as NAC） and used as carriers to load 7% Ce （named as Ce（0.07）/NAC） by impregnation method. The physical and chemical properties were investigated by thermogravimetric-differential thermal analysis （TG-DTA）, Brunauer-Emmett-Teller （BET）, X-ray diffraction （XRD）, X-ray photoelectron spectra （XPS）, scanning electron microscopy （SEM） and NH3-temperature programmed desorption （NH3-TPD） and NO-temperature programmed desorption techniques. The catalytic activities of Ce（0.07）/NAC were evaluated for the low temperature selective catalytic reduction （SCR） of NO with C3H6 using temperature-programmed reaction （TP-reaction） in NO, C3H6, 02 and N2 as a balance. The results showed that the specific surface area of Ce（0.07）/NAC was 850.8 m2/g and less than NAC, but Ce oxides could be dispersed highly on the acti- vated carbons. Ce oxides could change acid sites and NO adsorption as well as oxygen-containing functional groups of activated car- bons, and Ce4＋ and Ce〉 coexisted in catalysts. The conversion of NO with C3H6 achieved 70% at 280 ~C over Ce（0.07）/NAC, but with the increase of 02 concentration, heat accumulation and nonselective combustion were exacerbated, which could cause surface ashing and roughness, resulting in a sharp decrease of catalytic activities. The optimum 02 concentration used in the reaction system was 3% and achieved the high conversion of NO and the widest temperature window. The conversion of NO was closely related to the NO concentrations and [NO]/[C3H6] ratios, and the stoichiometric number was just close to 2：1, but the presence of H20 could af- fect the denitration efficiency of catalyst.

关键词： low temperature activated carbon cerium oxides selective catalytic reduction hydrocarbon rare earths

Templated synthesis of crystalline mesoporous CeO_(2) with organosilane-containing polymers: balancing porosity, crystallinity and catalytic activity

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Materials Futures 2022年第2期1卷 163-173页

作者： Qiang Luo Zichao Wei Hanyi Duan Lei Jin Rumasha N T Kankanamage Seth Shuster Steven L Suib James F Rusling Jie He Department of Chemistry University of ConnecticutStorrsCT 06269United States of America Polymer Program University of ConnecticutStorrsCT 06269United States of America Institute of Materials Science University of ConnecticutStorrsCT 06269United States of America Department of Surgery and Neag Cancer Center UConn HealthFarmingtonCT 06232United States of America School of Chemistry National University of Ireland GalwayGalwayIreland

We report the synthesis of ordered mesoporous ceria(mCeO_(2))with highly crystallinity and thermal stability using hybrid polymer templates consisting of *** organosilane-containing polymers can convert into silica-like nanostructures that further serve as thermally stable and mechanically strong templates to prevent the collapse of mesoporous frameworks during thermal-induced *** a simple evaporation-induced self-assembly process,control of the interaction between templates and metal precursors allows the co-self-assembly of polymer micelles and Ce^(3+)ions to form uniform porous *** porosity is well-retained after calcination up to 900℃.After the thermal engineering at 700℃ for 12 h(mCeO_(2)-700-12 h),mCeO_(2) still has a specific surface area of 96 m^(2) g^(−1) with a pore size of 14 ***_(2) is demonstrated to be active for electrochemical oxidation of ***_(2)-700-12 h with a perfect balance of crystallinity and porosity shows the fastest intrinsic activity that is about 84 times more active than bulk CeO_(2) and 5 times more active than mCeO_(2) that has a lower crystallinity.

关键词： mesoporous materials cerium oxides crystalline oxides electrocatalysis sulfite oxidation

Insights to Advanced Inorganic Nanoparticles,Nanorods,Nanofibers and Nanotubes:Preparation and Applications

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复旦学报（自然科学版） 2007年第5期46卷 707-页

作者： Bao-lian SU(Laboratoire de Chimie des Matériaux Inorganiques,The University of Namur,61 rue de Bruxelles,B-5000,Namur,Belgium) Laboratoire de Chimie des Materiaux Inorganiques The University of Namur61 rue de Bruxelles B-500NamurBelgium

1 Results Quasi one-dimensional nanostructured materials have received considerable attention due to their unique optical and electrical properties and potential applications in *** effort has been directed toward exploring novel synthetic methods and understanding the chemical and physical properties of these *** chemical vapor deposition and thermal evaporation,are proved to be efficient for the preparation of wirelike nanomaterials,however these methods are quite energy co...

关键词： nanotube nanofiber nanowire nanowire array titania manganese oxides cerium oxides zinc oxides