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MCM-41 supported nano-sized CuO-CeO2 for catalytic combustion of chlorobenzene

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Journal of Rare Earths 2020年第9期38卷 933-940,I0001页

作者： Jie Zheng Zhu Chen Jianfei Fang Zhuo Wang Shufeng Zuo Zhejiang Key Laboratory of Alternative Technologies for Fine Chemicals Process Shaoxing UniversityShaoxing 312000China Quality and Technical Supervision Inspection Center of Yongkang Yongkang 321300China

In this paper,MCM-41 was synthesized by a soft template technique and MCM-41 supported CuO-CeO2 nano-sized catalysts with different Cu/Ce molar ratios were prepared by a deposition-precipitation method.N2 adsorption,HRTEM-EDS,H2-TPR,XPS characterization,as well as catalytic activity and durability tests for the catalytic combustion of chlorobenzene(CB)were conducted to explore the relationship between the structure and catalytic performance of the *** is revealed that cuCe(6:1)/MCM-41 has the highest activity and can completely catalyze the degradation of CB at 260℃.The reasons for the high activity of the catalysts are as follows:MCM-41,a type of mesoporous material which has large pore size and large specific surface area,is suitable as a catalyst *** average diameter of nano-sized CuO and CeO2 particles is about 3-5 nm and adding CeO2 improves the dispersion of active component CuO,which are highly and evenly dispersed on the surface of *** results also explain why MCM-41 supported CuO-CeO2 with appropriate proportion can highly enhance the catalytic *** reason is that CeO2 acting as an oxygen-rich material can improve the mobility of oxygen species through continuous redox between Ce4^+and Ce3^+,and improve the catalytic performance of CuO for CB ***,CuCe(6:1)/MCM-41 also displays good durability for CB combustion,both in the humid condition and in the presence of benzene,making it a promising catalytic material for the elimination of chlorinated VOCs.

关键词： CuO-CeO2 MCM-41 nano-sized Chlorobenzene Catalytic combustion Rare earths

Synthesis and Characterization of nano-sized Boron Powder Prepared by Plasma Torch

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Plasma Science and Technology 2010年第5期12卷 577-580页

作者：黄志军吴青友李祥尚书勇戴晓雁印永祥 Center of Plasma Application School of Chemical Engineering Sichuan University

Hydrogen thermal plasma jet was employed to prepare nano-sized boron powder with hydrogen reduction of BCI3. The maximum yield of nano-sized boron powders was about 50% with the operational conditions of H2/BCl3 of 4.5：1, total feed of 4.9 m3/h, and plasma power of 25 kW. The samples were analyzed by X-ray diffraction （XRD）, field emission scanning electron microscopy （FE-SEM）, and inductively coupled plasma - mass spectrometry （ICP-MS）, inductively coupled plasma - atomic emission spectrometry （ICP-AES）, inductive combustion infrared absorption （ICIA） and infrared thermal conductivity of oxygen and nitrogen analyzer （ITCA）. The results show that the boron powders have different crystal structures with higher dispersion and purity. The average diameter is about 50 nm, and the purity is 90.29% or so. This new technology can use simple process to produce high quality boron powders, and is feasible for industrial production.

关键词： nano-sized boron powder thermal plasma ultra-fine powder

Modeling and analysis of nano-sized GMRs based on Co,NiFe and Ni materials

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Science China(Information Sciences) 2014年第2期57卷 216-229页

作者： YIN Cong JIA Ze MA WeiChao REN TianLing Institute of Microelectronics Tsinghua National Laboratory for Information Science and TechnologyTsinghua University

Magnetic simulation method is introduced to analyze giant magnetoresistances(GMRs)in nanoscale for nano-sized biosensors.A spin valve model with special gridding corresponding to the exchange interaction length is proposed to study the influence of easy axes,exchange coefcients,pinning fields and feature widths on magnetization reversals and hysteresis characteristics of nano-sized GMRs with diferent pinned layer and free layer materials of Co,NiFe and *** switching field is found to be almost linear with the pinning field and decrease with the absolute exchange coefcients and the feature widths for the nano-sized *** increase rate of each depends on the spin valve *** investigations into variations of the magnetization distribution reveal that the initial magnetization distribution and the magnetization reversal mode depend greatly on easy axes and materials The dependence on easy axes based mainly on the magnetocrystalline anisotropy is illustrated in detail.

关键词： nano-sized spin valve magnetization reversal switching field hysteresis antiferromagnetic coupling

Synthesis of Ag_(2)S nano-sized clusters and their chemical sensitizations in AgCl cubic and {100} tabular microcrystal imaging systems

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Science China Chemistry 2005年第6期48卷 516-522页

作者： LI Zhi ZHENG Tong CHEN Lijuan PENG Bixian YANG Li Technical Institute of Physics and Chemistry Chinese Academy of SciencesBeijing 100101China Beijing Satellite Manufacturing Factory Beijing 100080China

In recent years much attention has been devoted to AgCl emulsion owing to its se-rial advantages and inimitable *** in the research of this emulsion a thorny problem remains unsolved till now,which is the improvement in sensitivity is always accompanied with high fog *** this work 5 nm Ag_(2)S particles were prepared and used as novel sensitizers in AgCl cubic and{100}tabular microcrystal *** novel sensitizer shows an effective sensitizing ability for silver chloride emulsion,and it is superior to the traditional Na_(2)S_(2)O_(3) sensi-tizer because by using it comparatively high sensitivity can be obtained with lower fog *** the above sensitizing problem is going to be effectively *** discover the evolution mechanism of the sensitizer clusters and explain their excellent sensitizing properties,diffuse reflectance spectroscopy(DRS)was used as a probe on the AgCl microcrystal surface.

关键词： silver sulfide nano-sized silver chloride{100}tabular microcrystal chemical sensitization.

Comparative study of the explosion pressure characteristics of micro- and nano-sized coal dust and methane–coal dust mixtures in a pipe

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International Journal of Coal Science & Technology 2020年第1期7卷 68-78页

作者： Bo Tan Huilin Liu Bin Xu Tian Wang School of Emergency Management and Safety Engineering China University of Mining and Technology(Beijing)Beijing 100083China

Coal dust explosion accidents often cause substantial property damage and casualties and frequently involve nano-sized coal *** order to study the impact of nano-sized coal on coal dust and methane–coal dust explosions,a pipe test apparatus was used to analyze the explosion pressure characteristics of five types of micro-nano particle dusts(800 nm,1200 nm,45μm,60μm,and 75μm)at five concentrations(100 g/m3,250 g/m3,500 g/m3,750 g/m3,and 1000 g/m3).The explosion pressure characteristics were closely related to the coal dust particle size and *** maximum explosion pressure,maximum rate of pressure rise,and deflagration index for nano-sized coal dust were larger than for its micro-sized counterpart,indicating that a nano-sized coal dust explosion is more *** highest deflagration index Kst for coal dust was 13.97 MPa/(m·s),indicating weak *** 7%methane was added to the air,the maximum deflagration index Kst for methane–coal dust was 42.62 MPa/(m·s),indicating very strong *** indicates that adding methane to the coal dust mixture substantially increased the hazard grade.

关键词： A pipe test apparatus nano-sized Coal dust explosion Methane/coal dust explosion Pressure characteristics

The structural stability in nano-sized crystals of metals

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Science China(Technological Sciences) 2002年第5期45卷 485-494页

作者：孟庆平戎咏华徐祖耀 School of Materials Science and Engineering Shanghai Jiaotong University Shanghai China

The equation of phase equilibria in nano-sized crystal of metals has been established in terms of thermodynamic equilibrium. The thermodynamic parameters are calculated and the critical grain size for the stable high-temperature phase at room temperature is obtained. As an example, the critical grain size of β-Co at room temperature is determined at 35nm when the excess volume is 10%. The result agrees well with the experiment of Katakimi et al. The factors affecting the stability of β-Co are also discussed.

关键词： phase transformation, nano-sized crystal, energy of interface, critical size, excess volume.

Mechanism of expanding swept volume by nano-sized oil-displacement agent

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Petroleum Exploration and Development 2019年第5期46卷 991-997页

作者： LEI Qun LUO Jianhui PENG Baoliang WANG Xiaocong XIAO Peiwen WANG Pingmei HE Lipeng DING Bin GENG Xiangfei Research Institute of Petroleum Exploration&Development PetroChinaBeijing 100083China Key Laboratory of nano Chemistry(KLNC) CNPCBeijing 100083China

The effect of expanding swept volume by inanoW1.0 nanoparticles in ultra-low permeability core was studied by low-field nuclear magnetic resonance(LF-NMR)technology,and the mechanism of expanding swept volume was explained by oxygen spectrum nuclear magnetic resonance(17O-NMR)experiments and capillarity *** results of the LF-NMR experiment show that the nano-sized oil-displacement agent inanoW1.0 could increase the swept volume by 10%-20%on the basis of conventional water flooding,making water molecules get into the low permeable region with small pores that conventional water flooding could not reach.17O-NMR technique and capillary analysis proved that inanoW1.0 nanoparticles could weaken the association of hydrogen bonds between water molecules,effectively change the structure of water molecular clusters,and thus increasing the swept volume in the low permeable *** ability of weakening association of hydrogen bonds between water molecules of inanoW1.0 nanoparticles increases with its mass fraction and tends to be stable after the mass fraction of 0.1%.

关键词： nanoparticles nano-sized oil-displacement agent water flooding swept volume water molecular hydrogen bonding capillary action

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nano-sized LiCoO_2 Cathode for Use in Lithium-ion Cells

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复旦学报（自然科学版） 2007年第5期46卷 682-页

作者： J.Yamaki T.Doi S.Okada Institute for Mterials Chemistry and Engineering Kyushu University6-1 Kasuga-shi ukuoka-ken 816-8580Japan

1 Results Lithium ion batteries are widely used in many portable ***,their power density is not sufficient for use in electric *** of the most effective methods to improve the power density is the use of very fine cathode *** investigated new method,excess lithium method,of preparing nano-sized LiCoO2 *** begin with,lithium acetate and cobalt acetate are mixed by the molar ratio 9,13 or 21 to 1,*** the mixture is calcined at 600 ℃ for 6 ***,obtain...

关键词： nano-sized cathode Li-ion battery LiCoO2

Combustion and Ball Milled Synthesis of Rare Earth nano-sized Ceria Powder

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Materials Sciences and Applications 2011年第5期2卷 416-420页

作者： Ranjan Sen Siddhartha Das Karabi Das 不详

This paper reports a study on nanocrystalline ceria powder prepared by high energy ball-milling and combustion synthesis methods. The combustion synthesis was carried out using ceric ammonium nitrate as oxidizer and citric acid, glycine or citric acid plus glycine as fuel. The minimum crystallite size of ceria powder is obtained by combustion synthesis of ceric ammonium nitrate and citric acid. The ceria powder produced by combustion synthesis of ceric ammonium nitrate and citric acid and glycine has less agglomeration of particles than other techniques.

关键词： Ceramics Ball Milling Combustion Synthesis nano-sized Ceria X-Ray Diffraction