COMPOSITE STRUCTURES
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2024
·
IF 6.3
Junjie Xiao,Biao Liang,Bo Liu,Mengfei Feng,Hui Cheng,Kaifu Zhang
Soft actuators composed of shape memory alloy (SMA) wires embedded in polydimethylsiloxane (PDMS) matrix hold potential for shape-morphing structures and soft robots. However, SMA exhibits poor bonding with PDMS due to its smooth and nonpolar surfaces. Nanoparticles show promise in interfacial strengthening of polymer composites. In this work, KH590 was used to modify nano-Al 2 O 3 particles and deposited on the SMA surface, creating a three-dimensional nanostructure bridging SMA and PDMS to enhance interface strength. The synergistic effects of particle size and content of nano-Al 2 O 3 particles on the interface strength were investigated in detail. It founds that interfacial strength decreased exponentially with particle size at content of 1 wt%, while when the content exceeds 1 wt%, the interface strength firstly increases with the particle size and then decreases in a logarithmic trend. Specifically, the interface strength is enhanced by 110 % with 3 wt% 50 nm particles. The interface enhancement mechanism was also discussed. The proposed nanoparticle modification approach was to strengthen SMA/PDMS interphase by increasing and extending fracture path, consuming more fracture energy. Chemical cross-linking also contributed to interface enhancement. This work enhances understanding of interfacial bonding mechanisms and provides valuable guide for interfacial strengthening of SMA/PDMS.
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高影响因子
INFRARED PHYSICS & TECHNOLOGY
·
2024
·
IF 3.1
Yin Liu,Jie Wan,Yongbao Xiao,Dechao Yu
Glass forming regions of Al 2 O 3 -CaO-SrO (AlCaSr) system were systematically studied and clearly depicted by a combination of thermodynamic calculation method and traditional melt-quenching experiments. The glass forming region was first found with a composition range of Al 2 O 3 : 12–32 mol%, CaO: 43–68 mol%, and SrO: 20–36 mol%. Moreover, two representative glass compositions, 26.6Al 2 O 3 -49.4CaO-24SrO (AlCaSr-1) and 17.48Al 2 O 3 -58.52CaO-24SrO (AlCaSr-2), in central part of the experimental glass forming region and the corresponding glass doped with 1 mol% Er 2 O 3 , i.e., AlCaSr-1-Er and AlCaSr-2-Er, were selected and carefully prepared in our lab. Detailed investigations proved that the AlCaSr glasses had excellent comprehensive properties with high T g temperature (∼ 800 °C), wide transparency wavelength range (0.3–6 μm), and low maximum phonon energy (∼ 770 cm −1 ), and good 2.7 μm mid-infrared emitting properties via doping Er 3+ activators. These results highlight the potential application of AlCaSr glasses as infrared materials, and could benefit the development of high-performance infrared glasses.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2025
·
IF 8.3
Zhao-Mu Zhang,Jia-Hong Li,Yan-Neng Liang,Yuan Gao,Cheng-Xin Li
ScSZ is one of the traditional electrolyte candidates for solid oxide fuel cells (SOFCs) due to its excellent ionic conductivity. Nevertheless, its complex phase structure and high sintering temperature hinder further development. Herein, the effects of Yb 2 O 3 and Al 2 O 3 doping on conductivity and sintering ability as well as the long-term stability in ScSZ electrolyte are studied and discussed in detail. XRD and EIS tests revealed that the ZrO 2 electrolyte stabilized by 1 mol% Yb 2 O 3 and 10 mol% Sc 2 O 3 achieved a stable phase structure and high conductivity. Subsequently, the addition of 0.1 mol% Al 2 O 3 sintering aid reduced the densification temperature by more than 100 °C, achieving a density of over 96 % without significant decrease in ionic conductivity, with values of 0.12 S cm −1 in air at 750 °C. Long term stability test reveals that the ScSZ electrolyte doped with Yb 2 O 3 and Al 2 O 3 maintains a stable phase structure and exhibits no significant degradation in electrical performance after being held at 800 °C for 1080 h. In conclusion, the Yb 2 O 3 doped ZrO 2 electrolyte with 0.1 mol% Al 2 O 3 sintering aids exhibits a potential candidate material used in SOFCs.
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高影响因子
FUEL
·
2016
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IF 3.611
Libo Qin,Yang Zheng,Dianqing Li,Yunshan Zhou,Lijuan Zhang,Zareen Zuhra
The composite material HPW/NH 2 –Al 2 O 3 was successfully prepared by immobilization of phosphotungstic acid H 3 PW 12 O 40 (HPW) on the surface of amino functionalized spherical millimeter-sized mesoporous γ-Al 2 O 3 beads (NH 2 –Al 2 O 3 ), that featured high specific surface area, remarkable enhanced mechanical strength, chemical stability and low cost. This composite material was characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Brunner−Emmet−Teller (BET) and mechanical strength measurements. The experimental results showed that introduction of NH 2 group in between HPW and Al 2 O 3 surface not only provide strong binding sites for catalytic centers HPW to get high dispersion on the carrier surface but also prevent HPW from structural decomposition. As a consequence, the prepared HPW/NH 2 –Al 2 O 3 exhibited excellent catalytic performance in the oxidative desulfurization of model oil composed of dibenzothiophene (DBT) and n-octane. The 350 ppmw S of sulfur content in 20 mL of n-octane can be dropped down to 2.8 ppmw S in 2 h using 60 mg of HPW/NH 2 –Al 2 O 3 catalyst under the optimal conditions. Remarkably, the catalyst can be conveniently recycled by simple decantation method. After 10 times recycling, the oxidation desulfurization efficiency just dropped down slightly from 99.2% to 98.6%. The results indicate that synthesized HPW/NH 2 –Al 2 O 3 beads have great potential as a catalyst in oxidative desulfurization for special practical applications.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2019
·Vol. 30
·期 15
·14391-14404
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IF 2.195
Yu Xuemin,Wang Junchuan,Sun Ying,Zhang Xueqin,Lin Baoping
A series of nanocomposite films loaded with various concentrations of fillers were successfully synthesized by solution casting method (BSCTZS nanoparticles (NPs) as filler and polyimide (PI) as polymer matrix). To improve the dispersion and the physical–chemical properties of (Ba 0.87 Sr 0.04 Ca 0.09 )(Ti 0.86 Zr 0.08 Sn 0.06 )O 3 (BSCTZS) NPs surface, BSCTZS NPs were modified by Al 2 O 3 coating and modified Al 2 O 3 @Nb-BSCTZS NPs/PI nanocomposite films were prepared. The prepared modified Al 2 O 3 @Nb-BSCTZS NPs were characterized by X-ray diffraction (XRD) analysis, and scanning electron microscopy (SEM), and the dielectric properties of these composites were characterized in details. As a result, the nanocomposite films filled with 5 vol% Al 2 O 3 @0.4mol%Nb-BSCTZS nanoparticles exhibit an excellent energy density of 2.11 J cm −3 at 298 kV/mm, which is 48% over the original pristine PI (1.42 J cm −3 at 313 kV/mm). This work can provide a prospective solution for the preparation of composite film materials with high dielectric constant and high energy density.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2018
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IF 3.141
Wei Bi,Yanjie Hu,Wenge Li,Hao Jiang,Chunzhong Li
In this work, a nanoreactor combining layers of facile traditional two-dimensional (2D) material, hexagonal boron nitride (h-BN, which often called the white graphene) with Pt/Al2O3 catalyst was designed to exhibit higher stability, activity, and selectivity in automobile exhaust treatment. Characterization revealed that h-BN does coat on the surface of platinum and forms a distinct Pt@h-BN/Al2O3 core–shell nanostructure. This as-prepared catalyst possesses good thermal stability and selectivity, because of the excellent high-temperature tolerance and the multidefected structure of the h-BN shell; that is, small molecules such as CO and O2 can easily intercalate into the nanoreactor, while large molecules such as propylene are blocked out. Meanwhile, the intercalated reactants can achieve the conversion of CO to CO2 faster (ΔT100 = 20 °C) with the confinement effect. The study indicates that constructing a nanoscale confined environment with two-dimensional (2D) coating can enhance the performance of the catalyst in multiple aspects and simultaneously provide a good example for designing nanostructured catalysts with multifaceted improvement.
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JOURNAL OF AEROSOL SCIENCE
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2025
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IF 2.9
Shuting Lei,Yiyang Zhang,Zhu Fang,Xing Jin,Shuiqing Li
Spray flame synthesis has proven to be a promising method for the high-throughput production of multi-component nanoparticles with atomic-level mixing. However, the fast dynamic of flame synthesis presents significant challenges in precisely controlling the morphology and crystalline phase of the particles, especially for multi components. In this paper, we conduct parametric flame synthesis experiments to identify key factors affecting nanoparticle morphology and crystal phase of Y-Al nanoparticles, focusing on the effects of Y/Al atomic ratio, flame temperature, and precursor volatility. The results indicate that the particle morphology depends on the composition, changing from aggregates with sintering necks to spherical particles without sintering necks and back to aggregates as the Al content increases. This trend is consistent with the change in particle melting points, which initially decrease and then rise again. Thus, the variation in melting point causes changes in sintering time, which in turn affect the particle morphology. The particle crystalline phase gradually deviates from the target phase as the Al content increases. Raising the adiabatic flame temperature from 1551 °C to 2340 °C accelerates the diffusion of Al atoms into the lattice, increasing the target phase proportion in the synthesized particles from 66 % to 99 %. By adjusting the amount of 2-ethylhexanoic acid (EHA) added, the volatility differences between the precursors can be modified. The largest discrepancy in precursor volatility is observed when EHA was added at a 50 % equivalence ratio, resulting in only 6 % of the target phase YAH (YAlO 3 , hexagonal type) in the particles. Increasing the EHA addition to 120 % equivalent results in better matching of precursor volatilities, which leads to a significant increase in the target YAH phase to 98 %, demonstrating the critical role of simultaneous evaporation of different component precursors.
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ACS Applied Materials & Interfaces
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2020
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IF 8.758
Xi Chen,Qiang Li,Meng Zhang,Juanjuan Li,Songcai Cai,Jing Chen,Hongpeng Jia
CH4 production from CO2 hydrogenation provides a clean approach to convert greenhouse gas CO2 into chemical energy, but high energy consumption in this reaction still restrains its further application. Herein, we use a light-driven CO2 methanation process instead of traditional thermocatalysis by an electrical heating mode, with the aim of greatly decreasing the energy consumption. Under UV–vis–IR light irradiation, the photothermal CO2 methanation over highly dispersed Co nanoparticles supported on Al2O3 (Co/Al2O3) achieves impressive CH4 production rates (as high as 6036 μmol g–1 h–1), good CH4 selectivity (97.7%), and catalytic durability. The high light-harvesting property of the catalyst across the entire solar spectrum coupled with its strong adsorption capacity toward H2, CO2, CO, and abundant active sites are proposed to be responsible for the better photothermocatalytic performance of Co/Al2O3. Furthermore, a novel light-promotion effect is also revealed in CO2 methanation, where UV–vis light irradiation induces oxygen vacancies and improves the proclivity toward adsorption of H2, CO2, and CO, finally resulting in a significant enhancement of the photothermocatalytic activity for CH4 production. By concentrating the low-intensity light (120 mW/cm2) via a Fresnel lens, a photothermal CO2 conversion efficiency of more than 50% with a good CH4 selectivity (76%) is achieved on the optimal catalyst under a dynamic reaction system, which indicates the bright prospect of photothermal CO2 methanation.
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DOI
PubMed
高影响因子
FUEL
·
2025
·
IF 7.5
Chen-Xu Chen,Jing-Pei Cao,Nai-Yu Yao,Wen Tang,Wei Jiang,Chuang Zhang,Xiao-Yan Zhao,Xiao-Yu Qiao,Tungalagtamir Bold
Improving the catalytic efficiency and catalyst life of Pt/Al 2 O 3 catalyst for methylcyclohexane dehydrogenation is of great significance for the study of organic liquid hydrogen storage. In this work, the promotion effects of Ga and Ce on the substantial improvement of catalytic stability and activity over the Pt / Al 2 O 3 during the methylcyclohexane dehydrogenation were investigated. The catalyst with optimizing Ga and Ce loading (1.5 wt%) exhibits ∼99.76 % selectivity and H 2 evolution rate of 2102 mol/g Pt /min at 300 °C. In 100 h long-time reaction, the conversion of methylcyclohexane remains around 75 % with no significant decrease. The characterization results show that introducing proper amount of Ga and Ce helps Ga 3+ cations incorporate into the lattice structure of CeO 2 that increase concentration of oxygen vacancies and CeO 2 reducibility in the catalyst, which boost the capability of methylcyclohexane dehydrogenation and tolerance for coke formation. Thus, the excellent stability and activity are achieved over the GaCe-modified catalyst. This study may share new light on the rational construction of highly efficient Pt-based catalysts for methylcyclohexane dehydrogenation.
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APPLIED CATALYSIS B-ENVIRONMENTAL
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2014
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IF 6.007
Fredrik Gunnarsson,Moa Z. Granlund,Mattias Englund,Jazaer Dawody,Lars J. Pettersson,Hanna Härelind
We report on a high NO x reduction activity over Ag/Al 2 O 3 catalysts, using hydrogen produced in a fuel reformer. The focus of the study is to evaluate the performance of a hydrocarbon selective catalytic reduction (HC-SCR) catalyst in real conditions. Initially, the catalytic materials for the fuel reformer (Rh/CeO 2 -ZrO 2 ) and the HC-SCR (Ag/Al 2 O 3 ) were evaluated in separate bench-scale reactor setups. These two setups were subsequently joined into an integrated bench-scale reactor setup with the aim to evaluate the influence of the reformate on the HC-SCR activity in a controlled environment. In the final phase of the study a 4 wt.% Ag/Al 2 O 3 catalyst doped with 100 ppm(w) Pt was scaled up and tested in a pilot-scale reactor setup. The pilot-scale reactor setup enabled evaluation of the HC-SCR activity in real exhaust gases generated by a single cylinder engine (genset) together with a hydrogen-rich gas supplied from a fuel reformer. Commercial biodiesel (NExBTL) was used as reducing agent for the HC-SCR as well as fuel in the fuel reformer for both the bench-scale and pilot-scale experiments. This study gives an excellent link between evaluations of the catalytic materials, controlled bench-scale experiments and applied engine experiments, proving a viable concept for lean NO x reduction together with onboard hydrogen production. A NO x conversion of above 70% was reached at temperatures below 250 °C, in bench-scale experiments when hydrogen produced in the fuel reformer is added.
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APPLIED SURFACE SCIENCE
·
2020
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IF 6.182
Hao Zhang,Junyan Wang,Minjie Liu,Di Liu
Cu/Al 2 O 3 catalyst was developed by a double hydrolysis precipitation. Over the Cu/Al 2 O 3 catalyst, a continuous mode of N-methylations of nitroarenes with methanol was successfully achieved under the exogenous base- and H 2 - free condition. Methylation process of nitroarenes could be controlled just by adjusting reaction conditions, affording the desired N-monomethylanilines or N, N-dimethylanilines, respectively. The characterization displayed that the double hydrolysis precipitation method made active metal Cu surface enrichment and high dispersion, meanwhile endow Cu/Al 2 O 3 with more developed pore system, which were responsible for the higher performance of our catalyst relative to Cu/Al 2 O 3 -CP. Compared with the reported batch mode, our procedure possessed the merits of low cost, environment-friendliness, better controllability and wide universality.
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高影响因子
ACS Sustainable Chemistry & Engineering
·
2018
·
IF 6.14
Guohua Zhu,Kui Wu,Liang Tan,Weiyan Wang,Yanping Huang,Diyu Liu,Yunquan Yang
Magnetic colloidal sol was first prepared and added in the mixed solution of Ni(NO3)2 and Al(NO3)3. After the constant-pH coprecipitation and calcination, magnetic NiO–Al2O3@Fe3O4 mixed oxides were formed and used as supports for Pt-based catalysts. The activities of these magnetic Pt/NiO–Al2O3@Fe3O4 catalysts were tested in the hydrodeoxygenation (HDO) of phenols such as 4-ethylphenol, 4-methylphenol, and guaiacol. These exhibited high HDO activity, and aromatic hydrocarbons were produced through a coupling process of hydrodeoxygenation and dehydrogenation. The addition of Fe enhanced both the conversion and aromatic hydrocarbons selectivity, which was attributed to the electron transfer between metallic Pt and Fe. For example, after the liquid phase HDO of 4-ethylphenol at 300 °C and 2.0 MPa for 1.5 h, 97.9% conversion and 18.3% toluene selectivity were obtained. When the reaction time was prolonged to 8 h, ethylbenzene selectivity increased to 88.0%. Moreover, these Pt/NiO–Al2O3@Fe3O4 catalysts were easily recycled from the liquid reaction mixture by employing an external magnet, but the dehydrogenation stability needs to be further improved.
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