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Effects of cerium oxide on Ni/Al_2O_3 Catalysts for Decomposition of CH_4 and C_2H_4

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Journal of Rare Earths 2003年第4期21卷 427-429页

作者：杨咏来李文钊徐恒泳 Dalian Institute of Chemical Physics

Characteristics of carbon deposition of CH 4 and C 2H 4 decomposition over supported Ni and Ni Ce catalysts were studied by using a pulse reaction as well as BET, TPR, XPS and hydrogen chemisorption techniques. It is found that there is a metal semiconductor interaction (MScI) in the Ni Ce catalyst, and the effect of MScI on the carbon deposition of CH 4 decomposition is opposite to that of C 2H 4. A novel model of carbon deposition of CH 4 or C 2H 4 decomposition was proposed.

关键词： catalytic chemistry Ni/Al 2O 3 catalyst cerium oxide methane ethylene decomposition rare earths

Direct fabrication of cerium oxide hollow nanofibers by electrospinning

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Journal of Rare Earths 2008年第5期26卷 664-669页

作者：崔启征董相庭王进贤李梅 School of Chemistry and Environmental Engineering Changchun University of Science and Technology State Key Laboratory on High Power Semiconductor Lasers Changchun University of Science and Technology

Electrospinning technique was used to fabricate PVP/Ce（NO3）3 composite microfibers. Different morphological CeO2 nanofibers were obtained by calcination of the PVP/Ce（NO3）3 composite microfibers and were characterized by scanning electron microscopy （SEM）, Transmission electron microscopy （TEM）, X-ray diffraction （XRD）, thermal gravimetric and differential thermal analysis （TG-DTA）, and （FTIR）. SEM micrographs indicated that the surface of the composite fibers was smooth and became coarse with the increase of calcination temperatures. The diameters of CeO2 hollow nanofibers （300 nm at 600 ℃ and 600 nm at 800 ℃ ） were smaller than those of PVP/Ce（NO3）3 composite fibers （1-2 um ）. CeO2 hollow nanofibers were obtained at 600 ℃ and CeO2 hollow and porous nanofibers formed by nanoparti- cles were obtained at 800 ℃. The length of the CeO2 hollow nanofibers was greater than 50 um. XRD analysis revealed that the composite microfibers were amorphous in structure and CeO2 nanofibers were cubic in structure with space group O^5H - FM3m when calcination tem- peratures were 600-800 ℃. TG-DTA and FTIR revealed that the formation of CeO2 nanofibers was largely influenced by the calcination temperatures. Possible formation mechanism of CeO2 hollow nanofibers was proposed.

关键词： cerium cerium oxide nanofibers electrospinning rare earths

Reinforcement of natural rubber latex with silica modified by cerium oxide:preparation and properties

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Journal of Rare Earths 2016年第2期34卷 221-226页

作者：张福全廖禄生王永周汪月琼黄红海李普旺彭政曾日中 Chinese Agricultural Ministry Key Laboratory of Tropical Crop Product Processing Agricultural Product Processing Research InstituteChinese Academy of Tropical Agricultural SciencesZhanjiang 524001China Agriculture Ministry Key Laboratory of Biology and Genetic Resources of Rubber TreeRubber Research InstituteChinese Academy of Tropical Agricultural SciencesDanzhou 571731China

Variable masses of nano cerium oxide (CeO2) were added into nano silica (SiO2) to prepare the well-dispersed SiO2-CeO2 suspension (SiO2-CeO2), cetyltrimethyl ammonium bromide (CTAB) was used to adjust the compatibility of SiO2-CeO2 with rubber matrix, then SiO2-CeO2 modified by CTAB and curing formulas were mixed with fresh natural rubber (NR) latex to prepare NR/SiO2-CeO2 nanocomposites that contained 0–10 parts of CeO2 by a new emulsion compounding method. The morphologies, cure characteristics, mechanical properties and thermal-oxidative stability of NR/SiO2-CeO2 nanocomposites were investigated. The re-sults revealed that the presence of CeO2 in NR/SiO2-CeO2nanocomposites was favorable for enhancing the interaction between NR matrix and fillers, helped to get smaller SiO2-CeO2 particles with narrower particle size distribution, further improved the crosslink densities and mechanical properties of NR/SiO2-CeO2 nanocomposites vulcanizates. Meanwhile, the addition of CeO2 increased the active energy at least 4.66%, obviously improved the thermal-oxidative aging-inhibiting properties of NR/SiO2-CeO2 nanocomposites. Additionally, nanocomposites containing CeO2 promotedTg shift to high temperature direction, causing the nanocomposites featured higher tanδ at 0 oC and lower tanδ at 60 oC and exhibited comparable wet grip and lower rolling resistance when NR/SiO2-CeO2nano-composites were used in tire tread compound.

关键词： cerium oxide silica natural rubber latex emulsion compound reinforcement aging-inhibiting property glass transition temperature rare earths

Recent advances of cerium oxide nanoparticles in synthesis, luminescence and biomedical studies: a review

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Journal of Rare Earths 2015年第8期33卷 791-799页

作者：何立莹苏玉民蒋兰宏石士考 College of Chemistry and Materials Science Key Laboratory of Inorganic Nanomaterials of Hebei Province Hebei Normal University

Nanostructured cerium oxide （CeO2） commonly known as nanoceria is a rare earth metal oxide, which plays a technologically important role due to its versatile applications as antomobile exhaust catalysts, oxide ion conductors in solid oxide fuel cells, electrode materials for gas sensors, ultraviolet absorbents and glass-polishing materials. However, nanoceria has little or weak luminescence, and therefore its uses in high-performance luminescent devices and biomedical areas are limited. In this review, we present the recent advances of nanoceria in the aspects of synthesis, luminescence and biomedical studies. The CeO2 nanoparticles can bc synthesized by solution-based methods including co-precipitation, hydrothemlal, microemulsion process, sol-gel techniques, combustion reaction and so on. Achieving controlled morphologies and enhanced luminescence efficiency of nanoceria particles arc quite essential for its potential energyand environment-related applications. Additionally, a new fiontier for nanoccria particles in biomedical research has also been opened, which involves low toxicity, retinopathy, biosensors and cancer therapy aspects. Finally, the summary and outlook on the challenges and perspectives of the nanoceria particles are proposed.

关键词： cerium oxide nanoparticle controlled synthesis luminescence biomedical rare earths

Microscopic insights into hydrophobicity of cerium oxide:Effects of crystal orientation and lattice constant

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Journal of Materials Science & Technology 2022年第14期109卷 20-29页

作者： Dapeng Zhu Weiwei Liu Rongzhi Zhao Zhen Shi Xiangyang Tan Zhenhua Zhang Yixing Li Lianze Ji Xuefeng Zhang Key Laboratory for Anisotropy and Texture of Materials(MOE) School of Materials Science and EngineeringNortheastern UniversityShenyang 110819China Institute of Advanced Magnetic Materials College of Materials and Environmental EngineeringHangzhou Dianzi UniversityHangzhou 310012China

cerium oxide possesses intrinsic hydrophobic properties ascribed to the unique electronic ***,the relationship between the crystal structure and hydrophobicity of cerium oxide has not been systematically ***,it is experimentally and theoretically demonstrated that the water contact angle(105.9°)of the(111)surface is higher than that(91.7°)of the(220)surface,associated with the lower surface free energy(28.44 mN/m)of(111)surface than that(38.48 mN/m)of(220)***,cerium oxide films with(111)-terminated surface are annealed at 300℃ and 600℃ for1 h,*** lattice constant increases(5.4594Å300℃>the as-deposited),leading to the increased water contact angle(96.7°<96.8°<99.0°).The First-principles calculation provides microscopic insights into the wetting mechanism,originating from the weakened adsorption capacity of the(111)surface for water molecules with the increasing lattice constant.

关键词： cerium oxide Hydrophobicity Lattice constant Crystal orientation

Three-dimensional numerical simulation of heating and melting behaviors of cerium oxide powders in radio frequency thermal plasma

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Plasma Science and Technology 2023年第5期25卷 147-158页

作者：李雪迎周志伟李容毅朱海龙 Institute of Theoretical Physics Shanxi UniversityTaiyuan 030006People’s Republic of China College of Physics and Electronics Engineering Shanxi UniversityTaiyuan 030006People’s Republic of China

The present study aims at the numerical simulations of the melting process of cerium oxide particles in RF thermal *** physical model and the calculating method were described firstly;the interaction between cerium oxide particles and plasma was analyzed;specific attention was given to the effects of particle initial size,injection velocity on the particle melting and trajectory in *** influence of the temperature field and velocity field distribution of the plasma around the particle trajectory on the melting effect is analyzed,and the relationship between the heat absorption efficiency of the particles and the particle size reduction process is further *** is also found that there exists an optimal particle initial injection velocity which led to a more concentrated final particle size distribution and a more significant reduction of particle *** results could provide effective guidance for understanding the plasma spheroidization process of uranium dioxide and cerium dioxide powder particles.

关键词： particle behaviors radio frequency thermal plasma spheroidization cerium oxide

Microstructure and properties of cerium oxide/polyurethane elastomer composites

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Rare Metals 2021年第12期40卷 3685-3693页

作者： An Xie Shen-Wei Mao Tian-Jiang Chen Hui Yang Ming Zhang School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225000China

In general, inorganic filler/polyurethane elastomer(PUE) composites possess favorable properties, such as modulus, chemical resistance, and heat stability, are promising for broadening the application area of polyurethanes(PU). For the experiments, a series of cerium oxide(CeO_(2))/PUE composites were prepared with different sizes and appearance of CeO_(2), and different mixing methods as well. CeO_(2) particles with different sizes were added into PUs during the formation of urethane linkage and the chain-extend process, respectively. The morphology along with mechanical properties, thermal properties of the composites were studied. The results suggest that the size of CeO_(2) and mixing methods influence the microstructure of PUs which has profound effect on properties of these composites. The composites tend to form more quantity of hard domains(HDs) with small size when CeO_(2) particles were added before the formation of urethane linkage, whereas Ce O2 particles increase the size of HDs when added with chain extender into PU prepolymer.

关键词： cerium oxide Microstructure Polyurethane elastomer

Synthesis of β-SiC/SiO_2 core-shell nanowires with the assistance of cerium oxide

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Journal of Rare Earths 2010年第3期28卷 365-368页

作者：于伟鹏郑瑛杨娥邱健斌兰瑞芳 College of Chemistry and Materials Science Fujian Normal University

The β-SiC/SiO2 core-shell nanowires with the 'stem-and-node' structure were synthesized in the presence of cerium oxide by the carbothermal reduction of the starch-SiO2 hybrids *** samples were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),high-resolution transmission electron microscopy(HRTEM) and energy-dispersed X-ray(EDX).The results showed that the nanowires consisted of a 20-35 nm diameter crystalline β-SiC core wrapped with a 2-5 n...

关键词： β-SiC/SiO2 core-shell nanowires carbothermal reduction cerium oxide vapor-liquid-solid(VLS) mechanisms rare earths

Antibacterial properties of cerium oxide nanoparticles:Recent progresses and future challenges

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Particuology 2024年第10期93卷 264-283页

作者： Heishu Zheng Jiajing Tang Yanhua Wei Xi Deng Yingjuan Zhang Xiangyu Ma Xudong Jiang Zhi Ping Xu Hongbing Liao College&Hospital of Stomatology Guangxi Medical UniversityNanning530021China Guangxi Key Laboratory of Oral and Maxillofacial Rehabilitation and Reconstruction Guangxi Medical UniversityNanning530021China The First Affiliated Hospital of Guangxi Medical University Nanning530021China School of Medicine Guangxi University of Science and TechnologyLiuzhou545005China Institute of Biomedical Health Technology and Engineering and Institute of Systems and Physical Biology Shenzhen Bay LaboratoryShenzhen518107China Australian Institute for Bioengineering and Nanotechnology(Bld 75) The University of QueenslandSt LuciaQueensland 4074Australia

Use of cerium oxide nanoparticles(CeO_(2) NPs)to optimize management of resistant microorganisms has received increasing attention due to non-specific activity of inorganic antibacterial *** the mechanism of action is essential to elucidating the antibacterial activity of CeO_(2) NPs against ***,this review aims to summarize the antibacterial mechanisms of CeO_(2) NPs and correlate the structural and physicochemical properties of CeO_(2) NPs to their antibacterial *** further summarize the strategies for the improvement of the antibacterial performance of CeO_(2) NPs and provide our opinions for future challenges as a conclusion.

关键词： Nanoparticles cerium oxide Antibacterial activity Nanozyme Fenton reaction