JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2016
·
IF 2.933
Xiaoxia Hu,Lina Yang,Lingyu Li,Dieni Xie,Haiyan Du
Freeze casting was employed to fabricate alumina fiber-based porous ceramics . The binder particles were rejected by ice crystals from the gaps of the network to fibers and bonded them to obtain strong and light network. The effects of fiber character, cooling temperature and slurry viscosity on the structure formation were investigated. The structure and properties of the fibrous porous ceramics were determined by two factors: the fiber network and the dispersion of binders. The cooling temperature and slurry viscosity affected the dispersion of the particles rejected by the solidification front while the fiber length affected the fiber network. The material with optimal properties was obtained with 5 wt% PVA, 5 wt% silica sol and 1 vol% alumina fibers when freezing at −20 °C. The bulk density was 0.199 g/cm 3 and the specific strength was 3.860 N m/kg.
研究领域:
材料科学
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陶瓷工程
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2017
·
IF 3.133
Yuanfeng Wu,Xianghai Song,Fufeng Cai,Guomin Xiao
A series of Ce-NiO catalysts prepared by co-precipitation method were tested for glycerol transesterification with diethyl carbonate (DEC) to produce glycerol carbonate (GC). The microstructural and physicochemical properties of the catalysts were determined by XRD , XPS , SEM, EDX, CO 2 -TPD, N 2 -adsorption, FT-IR, and TG-DTG. The results showed that the particle size (100–350 nm) of the Ce-NiO was smaller than that of pure NiO (400–900 nm), suggesting addition of Ce in the catalyst synthesis could lessen the aggregation or facilitate the dispersion of NiO particles. The highest catalyst activity was observed over the Ce-NiO catalyst with Ce/Ni atomic ratio of 0.2 and calcined at 400 °C. 94.14% of glycerol conversion and 90.95% selectivity to GC were obtained over this catalyst under the optimum conditions (5 wt.% catalyst of glycerol, 85 °C, 8 h, glycerol/DEC ratio of 1:3). This catalyst can be reused up to three cycles with a slight decrease in its catalytic activity. It was found the well dispersed NiO particles and the strong basic sites derived from the substitution of Ce 4+ by Ni 2+ in the CeO 2 lattices synergistically promoted the glycerol conversion.
研究领域:
催化化学
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材料科学
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可再生能源
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DOI
高影响因子
CATALYSIS LETTERS
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2016
·Vol. 146
·期 8
·1408-1414
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IF 2.294
Kang Yumei,Bu Xiaosong,Wang Guangyu,Wang Xiaoqing,Li Qianwen,Feng Yisi
Abstract A series of bimetallic Cu samples (Cu–Pt/SiO 2 , Cu–Pd/SiO 2 , Cu–Ag/SiO 2 , Cu–Ni/SiO 2 ) were prepared by wetness impregnation method, then investigated for hydrogenolysis of glycerol to 1,2-propanediol (1,2-PDO). We furthered the study and found that Cu–Pt/SiO 2 got the smallest particle size and greatest dispersion. Besides, it was found that Pt promoted reduction of Cu 2+ . Compared with other Cu–Pt molar ratio, Cu–Pt/SiO 2 (1:0.2) was the preferable catalyst for hydrogenolysis of glycerol to 1,2-PDO. It is worth noting that Cu–Pt/SiO 2 presented the highest activity with a 96 % selectivity to 1,2-PDO and a nearly 100 % conversion of glycerol at 473 K, 40 bar initial H 2 pressure, 12 h, which is much higher activity than monometallic Cu/SiO 2 , Pt/SiO 2 and other bimetallic Cu samples. Meanwhile, the used Cu–Pt/SiO 2 catalyst still preformed high activity. Furthermore, it was found that the presence of Pt decreased the aggregation of particles during the hydrogenolysis of glycerol. Graphical Abstract
研究领域:
催化化学
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材料科学
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可再生能源
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产品关联
DOI
高影响因子
RSC Advances
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2016
·Vol. 6
·期 113
·111976-111981
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IF 3.289
Shuping Zhao,Zhenglong Yang,Wei Jiang,Liying Kang,Na Liu,Yanfeng Meng,Changmei Sun
Sn/carbon nanofibers with well dispersed Sn nanoparticles embedded in carbon nanofibers were fabricated by an electrospinning process. A SnO2 sol was used as the Sn precursor in order to improve the compatibility of tin/carbon composites and prevent Sn nanoparticles from severe agglomeration upon thermal treatment. When evaluated as a binder-free anode for lithium ion batteries, the Sn/carbon nanofibers deliver a high specific capacity of 583 mA h g−1 after 100 cycles and good cycling performance with coulombic efficiency up to 99%. The high lithium storage capability is mainly attributed to the optimized structure features including the well dispersed tin nanoparticles, high porosity, and the cushion effect of the carbon nanofibers.
研究领域:
材料科学
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能源存储
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
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2023
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IF 6.4
T. Zhang,H.W. Deng,Z.M. Xie,Y.W. Zhuang,S.Y. Peng,G. Hu,H. Lin
Improvement of the stability of nanocrystalline (NC) materials is always a challenge. In this paper, the high thermal stability is achieved in a representative NC W alloy by combining nano-segregation of Ti solute to W grain boundary (GBs), and in-situ formation of nano Ti–Zr–O particles, which provide both thermodynamic and kinetic stabilization effects through solute dragging and particle pinning. The recrystallization temperature of this bulk NC W alloy reaches up to 1600 °C, and these nanometric microstructures maintain stable under a long-time and high-temperature ordeal up to 1200 °C for 120 h. And its microhardness and micro-compressive yield strength are ∼17.0 and 5.14 GPa, respectively. In addition, this bulk NC W alloy has high irradiation stability due to the high densities of stabled GBs and phase boundaries. This work demonstrates the possibility of attaining high-stability bulk NC materials in terms of segregation of solutes at GBs and in-situ formation of ultrafine nanoparticles with a coherent interface with the W matrix.
研究领域:
材料科学
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纳米技术
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产品关联
DOI
高影响因子
CHEMPHYSCHEM
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2024
·Vol. 25
·期 5
·e202300960
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IF 2.3
Wen Chao Chen,Shi Jia Li,Hai Yan Xu,Shao Hui Xu,Guang Tao Fei
Graphical Prussian Blue analogues (PBAs) with different particle dispersions were prepared using co-precipitation method. In terms of electrochemical performance, PBAs with good particle dispersion show more pronounced advantages at high rates. The underlying mechanism is that PBAs with well-dispersed particles exhibit shorter Na + diffusion channels and fewer interfacial impediments during the charge-discharge process, resulting in faster sodium ion diffusion kinetics. Prussian blue analogues (PBAs) have advantages such as high voltage and low cost, making them one kind of the promising positive electrode materials for sodium-ion batteries. Particle dispersion is a key physical parameter of electrode materials, and understanding its impact on electrochemical performance is a prerequisite for obtaining high-performance PBAs. In this article, two PBAs samples with different particle dispersion were synthesized through sodium citrate-assisted co-precipitation method by means of staying and stirring. The influence of particle dispersion on electrochemical performance was investigated through polarization curve and AC impedance tests. It was found that PBAs with well-dispersed particles exhibited excellent rate performance, with a capacity of ~120 mAh g −1 at 1 C rate and a capacity retention of 75 % after 100 cycles. The capacity retention rate could reach 63 % at 5 C rate, far higher than that of PBAs samples with poor particle dispersion. From the perspective of electrochemical kinetics analysis, it has been shown that PBAs with well-dispersed particles exhibit smaller electrochemical polarization and faster Na + diffusion reaction kinetics, which are key factors in achieving excellent rate performance.
研究领域:
材料科学
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电化学
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DOI
PubMed
高影响因子
APPLIED CATALYSIS A-GENERAL
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2025
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IF 4.8
Mengyao Luo,Longli Bo,Sining Huang,Haiguang Wang,Zhiyun Yang,Danjun Wang,Ying Yang,Zhe Li,Lu Wang
Adding polyethylene glycol (PEG) can lessen the shedding of coating and improve the dispersion of active particles for monolithic catalysts. In this study, a series of Cu-Mn-Ce-O x (P x )/TiO 2 (P x )/CH catalysts were prepared with different PEG molecular weights (P x , x = 200, 1000, and 2000) to explore the effect of P x addition on the structure and activity of the catalysts in microwave catalytic combustion of toluene. The research showed that P x addition (1 wt% dosage to titanium sol) to coating reduced the particle size of titanium sol and decreased the shedding rate of TiO 2 coating 0.9–0.93 %, and P x addition (3 wt% dosage to CH's water absorption) to active components further lessened the shedding rate of the catalysts 1.93–2.04 %. Under an initial toluene concentration of 1500 mg/m 3 and a gas hourly space velocity of 2260 h −1 , Cu-Mn-Ce-O x (P 1000 )/TiO 2 (P 1000 )/CH owned the highest catalytic activity and its complete removal temperature (T R100 ) and mineralization temperature (T M100 ) to toluene were 180℃ and 218℃, respectively, which were lower 33℃ and 16℃, 56℃ and 58℃ than Cu-Mn-Ce-O x /TiO 2 (P 1000 )/CH and Cu-Mn-Ce-O x /TiO 2 /CH catalysts separately, and its activity maintained steadily with toluene removal efficiencies of 99–91 % over 12 h. The improved activity is attributed to the uniform dispersion of active particles, larger specific surface area, and increased adsorbed oxygen, facilitated by pore-forming and steric-hindrance effects of P x . Electron transfer among Mn 4+ /Mn 3+ /Mn 2+ , Cu 2+ /Cu + , and Ce 4+ /Ce 3+ promoted the oxidation of toluene under microwave irradiation. Therefore, the research provides technological support for developing transition metals-based catalysts for industrial VOC waste gas treatment.
研究领域:
环境科学
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催化化学
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产品关联
DOI
高影响因子
ACS Catalysis
·
2019
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IF 12.221
Yan-Rong Liu,Xue Li,Wen-Min Liao,Ai-Ping Jia,Yue-Juan Wang,Meng-Fei Luo,Ji-Qing Lu
The Pt catalysts supported on hexagonal BN (Pt/BN) are highly active and stable for propane combustion, with the highest specific reaction rate of 92.3 μmol gPt–1 s–1 and turnover frequency of 0.037 s–1 obtained on a 0.2Pt/BN catalyst at 220 °C. The Pt oxide in the catalyst could be partially reduced to the metallic state by propane during the reaction, which is beneficial for the improvement of activity, indicating that metallic Pt might be the active sites. The highly dispersed Pt particles stabilized at the grain boundary of BN could be more easily reduced in the reaction than those on the surface and thus are more active. Moreover, kinetic investigation reveals that the apparent activation energy of the Pt species at the grain boundary (111.6 ± 8.0 kJ mol–1) is much lower than that on the surface (172.4 ± 16.5 kJ mol–1), suggesting different reaction pathways on these catalysts and the possible participation of the grain boundary of the BN support in the reaction.
研究领域:
催化化学
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环境化学
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材料科学
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表面科学
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能源化学
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DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 50
·31582-31587
·
IF 3.108
Yuying Zheng,Peishan He,Yanxiong Fang,Xu Yang,Huagen Liang
Selective hydrogenation of phenol is of great significant for the production of Nylon 6. Herein, highly efficient and stable Ir promoted Pt catalysts for the hydrogenation of phenol are prepared by deposition of Pt–Ir nanoparticles onto hollow mesoporous silica spheres (HMSs) through a facile wet-impregnation and H2 reduction method. The obtained PtIr/HMS catalyst with Ir/Pt molar ratio of 0.1 shows a highest hydrogenation rate of 4255 mmol h−1 gPt−1 with cyclohexanone selectivity of 85% at 50 °C and 0.5 MPa of pH2, which is 3 times and 8.6 times higher than that of the mono Pt/HMS catalyst and commercial Pt catalyst, respectively. The trace addition of Ir promoter essentially contributes to the enhanced hydrogenation activity by improving the metal dispersion of Pt nanoparticles and promoting the charge transfer between the Pt and Ir. This work provides an effective protocol in developing high performance catalysts for phenol hydrogenation under mild reaction conditions.
研究领域:
催化化学
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材料科学
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有机合成
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纳米催化
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绿色化学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
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2024
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IF 6.3
Jun Li,Peng Huang,Xiaoqi Cheng,Rongmin Wang,Yufeng He,Pengfei Song
Bacterial contamination in water bodies is potentially transmissible to humans, making water bodies a major pathway of bacterial transmission. However, existing hydantoin copolymer nanoparticles did not achieve the regulation of nanoparticle dispersion and particle size by adjusting the ratio of hydrogen-donors and hydrogen-acceptors. To tackle this issue, amphiphilic hydantoin copolymer nanoparticles (P(VBDH-BA-NVP)NPs) were synthesized by modulating hydrogen-donors and hydrogen-acceptors using emulsion polymerization, and amphiphilic N-halamine copolymer nanoparticles (P(ClV-BA-NVP)NPs) were subsequently prepared via chlorination treatment. Impressively, nanoparticle dispersion and particle size were modulated by adjusting the ratio of hydrogen-donors and hydrogen-acceptors. With the increase of nanoparticle dispersion and the decrease of particle size, the active chlorine content was gradually enlarged, and the antibacterial performance was progressively enhanced against Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ). More importantly, amphiphilic N-halamine copolymer nanoparticles with two-dimensional dispersing (2DD-P(ClV-BA-NVP)NPs) exhibited excellent antibacterial properties, which benefited from the dual coordination of direct contact killing and indirect release killing in aqueous medium. Through designing P(VBDH-BA-NVP)NPs with hydrogen bond interactions, this approach aims to achieve the constitutive relationship between the effective exposure of active sites and the antibacterial effect.
研究领域:
材料科学
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纳米技术
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高分子化学
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环境科学
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微生物学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）