CERAMICS INTERNATIONAL
·
2017
·
IF 2.986
Shuaishuai Lu,Jingde Zhang,Yuanyuan Sun,Huichao Liu
CuO-CeO 2 -ZrO 2 /cordierite catalysts have been successfully prepared by the impregnation reduction method. The effects of processing parameters such as the condition of reduction process, calcination temperature, the addition of surfactant on the size and shape of catalyst particles were studied by X-ray diffraction (XRD), BET surface area measurements, and scanning electron microscopy (SEM). The catalytic performance of the as-prepared catalysts for CO oxidation were evaluated by using a microreactor-GC system. The results indicate that the processing parameters influence greatly the size and shape of catalyst particles. Fragmental shape catalysts were formed when the impregnated samples were reduced in the thermostat water bath. However, spherical-like particles were obtained by ultrasonic-assisted in the reduction process. Tiny flower-like catalyst particles were found when the surfactant were used. When the calcination temperature decreased, the grain size of catalysts has reduced, and the catalytic activity for CO oxidation has been improved. The introduction of ultrasonic and surfactant resulted in larger specific surface area and better catalytic performance.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 23
·5824
·
IF 3.1
Guoyu Zhang,Lu Li,Yanxin Nan,Peng Li,Tao Deng,Zhipeng Lei,Yuanyuan Li,Jianhua Zhang
In this work, the effects of different sintering temperatures and TiO2concentrations on the dielectric properties of ZrO2and Nb2O5pre-doped CaCu3Ti4O12(CCTO) ceramics were investigated. These doped ceramics were sintered at temperatures of 1020, 1030, and 1040 °C, exhibiting the lowest dielectric loss of 0.01, which consistently remained below 0.03 across a wide frequency range from 10 to 105Hz. Simultaneously, they maintained a high dielectric constant of more than 3000 and remarkably met the requirements for an X8P capacitor (Δε′ ≤ ±10% at temperature range from −55 to 150 °C). It was clarified that TiO2doping increased grain boundary resistance, leading to the reduced dielectric loss, and elevated the grain boundary activation energy, thereby enhancing the temperature stability. The TiO2-doped CCTO-based ceramics also demonstrated reduced sensitivity to variations in sintering temperature, highlighting their excellent manufacturability. This characteristic holds great promise for the fabrication of CCTO-based ceramics, which usually exhibit poor repetitiveness.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2021
·
IF 6.165
Liyu Chen,Jiaxin Yang,Youjian Yang,Jiangyu Yu,Xianwei Hu,Wenju Tao,Zhaowen Wang
The fluorine salt system is a potential electrolyte for the preparation of metals and alloys from metal oxides via molten salt electrolysis. The solubility of ZrO 2 in KF–AlF 3 –Al 2 O 3 molten salts (KF/AlF 3 molar ratio = 2.1–2.8, Al 2 O 3 content = 0–9 wt%) was measured using the isothermal saturation method in this study. The influence of temperature and electrolyte composition on ZrO 2 solubility was analyzed. The dissolution mechanism of ZrO 2 was then determined based on the analysis of X–ray diffraction and Raman spectroscopy results. The experimental results show that the solubility of ZrO 2 in the 2.4KF–AlF 3 molten salt at 1233 K could reach up to 6.62 wt%. Besides, the solubility of ZrO 2 increase with the increase of temperature, the decrease of KF/AlF 3 molar ratio and Al 2 O 3 content. X-ray diffraction and Raman spectroscopy analyses show that the dissolved ZrO 2 in KF–AlF 3 molten salts existed in the form of [Zr 2 O 2 F 6 ] 2− and [ZrF 6 ] 2− complex ions under melting and cooling conditions, respectively. And the dissolution process of ZrO 2 in KF–AlF 3 molten salts can be described using a mass transfer control model.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2017
·
IF 2.594
Zhaopeng Liu,Yan Xu,Zhenhua Li,Baowei Wang,Weihan Wang,Xinbin Ma,Renjie Liu
In this paper, Ce 0.2 Zr 0.8 O 2 composite supports were prepared by different Ce-addition methods including impregnation of cerium (CeZr-imp), impregnation of citric acid and cerium (CeZr-CA) simultaneously and deposition precipitation method (CeZr-DP), respectively. The as-prepared supports were applied to prepare 10 wt% MoO 3 /Ce 0.2 Zr 0.8 O 2 catalysts for sulfur-resistant methanation . The N 2 adsorption/desorption, X-ray diffraction (XRD), Raman spectroscopy (RS), X-ray photoelectron (XPS), temperature-programmed reduction by hydrogen (H 2 -TPR) were undertaken to get textural properties, morphological information and structures of the catalysts. The results showed that MoO 3 was highly dispersed on the surface of these three supports and Ce was mostly of coexisted in Ce 4+ /Ce 3+ redox pairs. Compared with Mo/CeZr-imp, the CO conversion increased by 10% and 15% for Mo/CeZr-CA and Mo/CeZr-DP, respectively. This was mainly attributed to the larger specific surface area, Ce 3+ concentration and content of active MoS 2 on the surface of catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
CyTA-Journal of Food
·
2019
·
IF 1.605
Min Pang,Lulu Cao,Lili Cao,Yi She,Hualin Wang
The properties of manufactured nisin-ZrO2/poly (vinyl alcohol)-wheat gluten (ZPWG) films were characterized. The formation of hydrogen bonds among the PVA, WG, and ZrO2 units were detected and caused a decrease in the film crystallinity. Also, the degradation rate was increased with WG content. As expected, the addition of WG and ZrO2 influenced the light transmission, tensile properties, gas permeability and water vapor permeability of the films. Nisin-loaded films presented a low initial burst release of the antimicrobial agent, followed by a gradual release. The initial diffusion of nisin (Mt/M∞<2/3) from the ZPWG film was formulated by the Fickian diffusion equation, showing a linear relationship (R2 > 0.998) between Mt/M∞ and t1/2, and the diffusion coefficient D increased with increasing WG content. Antimicrobial activity testing of nisin-ZPWG films with 40 wt% WG showed excellent inhibitory activity against Staphylococcus aureus, indicating its potential as a new active food packaging material.
研究领域:
食品科学
·
材料科学
✓ 已验证
DOI
高影响因子
ORGANIC ELECTRONICS
·
2021
·
IF 3.721
Yijia Zhou,Xiaofeng Zhao,Yingna Zhang,Feng Dou,Shuhong Wang,Cheng Wang
The poly[2,7-9-(9-heptadecanyl)-9H-carbazole-co-benzo[4,5] imidazole[2,1-a]isoindol-11-one] (PCz-O) was synthesized by Suzuki coupling reaction, which structure was verified by FT-IR, 1 H NMR and 13 C NMR. The spin coating method was used to prepare RRAM devices based on PCz-O: ZrO 2 nanoparticle active layer, and the devices exhibited ternary switching. Through a series of performance tests, both pure polymer device and composited with ZrO 2 NPs devices had ternary storage characteristics. Among them, the content of composited with 8 wt% ZrO 2 showed the most excellent ternary storage characteristics. The ON/OFF current ratio was 2.60 × 10 4 , and the threshold voltage V th1 / V th2 was −0.60 V/-1.00 V. The current is stable for 10000 s in both ON/OFF states. After 3300 times of reading, the switch state current of the devices had slight variation. In addition, the switching mechanism of the device was also discussed. Through carefully testing and analyzing, the devices had good stability and durability, and had potential application value in terms of data storage.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
MATERIALS CHARACTERIZATION
·
2022
·
IF 4.537
Qian Ma,Qingliang Shan,Changrong Chen,Qiankun Xu,Yewei Wang,Yuqian Zhou,Anze Shui
To obtain aluminum titanate (AT, Al 2 TiO 5 ) ceramics with excellent mechanical properties , the ZrO 2 was introduced into AT flexible ceramic to modify the microstructure of it. Results show that ZrO 2 can significantly improve the mechanical properties of AT flexible ceramics. When the addition of ZrO 2 is 8 wt% and 12 wt%, the optimal strain and strength increase by ~52% and ~ 46%, respectively. The statistical results show that ZrO 2 can not only refine the AT grains but also improve the aspect ratio, which leads to more events of grain pull-out and transgranular fracture . Since the generated ZrTiO 4 is pinned in the AT grain boundary microcracks , the phenomenon of branching and deflection of main crack will increase, rising the resistance of main crack propagation . It is expectable that the discovery of this work is benefitted to solve the brittle limitation of ceramics.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
DIAMOND AND RELATED MATERIALS
·
2024
·
IF 4.3
Siyue Zhang,Lin Zhu,Zheng Ai,Baoli Wang,Ahmad Mansoor,Yan Zhang,Wei Sun
By using carbon nanotube (CNT) as the carrier, Ni as the active center and ZrO 2 as the modifier, an efficient electrocatalytic material (ZrO 2 -Ni/CNT) is designed and synthesized in this paper. The structure and properties of the catalyst are characterized by various instrumental analysis methods such as SEM, TEM, XRD and XPS. The electrochemical test results show that the addition of ZrO 2 can significantly improve the catalytic performance of this catalyst in the electrochemical water splitting. In an alkaline solution, ZrO 2 -Ni/CNT catalyst displays an exceedingly low overpotential of 169 mV and 249 mV at the current density of 10 mA cm −2 towards hydrogen evolution reaction and oxygen evolution reaction, respectively. This work shows that the modification of ZrO 2 can improve the electrocatalytic activity of Ni-based materials, and the modification strategy can be applied to improve the electrocatalytic activity of commercial Ni-based electrode materials.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Vietnam Journal of Chemistry
·
2023
·Vol. 61
·期 4
·461-469
·
IF 0.9
Nguyen Thi Dieu Linh,Khuc Duong Huy,Nguyen Thi Kim Dung,Ngo Xuan Luong,Thai Hoang,Do Quang Tham
The 3D printing PMMA/ZrO 2 filaments with a diameter of 1.75 ± 0.05 mm were fabricated by using a single-screw extruder at temperatures of four heating zones of 190, 200, 210, and 210°C. Testing samples were prepared from the extruded filaments by using a fusion deposition modeling 3D printer and a Haake MiniJet piston injection molding machine. Fourier transform infrared spectroscopy, mechanical properties, field emission scanning electron microscopy (FESEM), differential scanning calorimetry, and thermogravimetric analysis of the filaments were investigated. It was suggested the formation of physical and molecular interactions between surface hydroxyl groups of ZrO 2 nanoparticles and C-O-C groups of PMMA in the PMMA/ZrO 2 filaments. FESEM images of the filaments indicated the good dispersion of ZrO 2 nanoparticles in the PMMA matrix, nevertheless, there was still the formation of clusters of ZrO 2 nanoparticles in the nanocomposite filaments. The incorporation of nano ZrO 2 increased the thermal properties, bending, and tensile moduli of PMMA. The mechanical properties of the 3D-printed samples were lower than those of the molded samples. However, the bending strength of the 3D-printed samples was much higher than 50 MPa, bending modulus was much higher than 1800 MPa, as required for acrylic bone cement (in ISO 5833:2002).
研究领域:
材料科学
·
化学工程
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
Environmental Science-Nano
·
2024
·Vol. 11
·期 3
·881-888
·
IF 5.8
Yingkang Chen,Cheng-Wei Kao,Tao Luo,Hang Zhang,Yan Long,Junwei Fu,Zhang Lin,Liyuan Chai,Ting-Shan Chan,Min Liu
Tetrafluoromethane (CF4), as the simplest and most abundant perfluorocarbon in the atmosphere, is listed in the ‘United Nations Framework Convention on Gases’ for its strong greenhouse potential. With its increasing atmospheric emissions, catalytic hydrolysis of CF4 as a non-toxic by-product method has been extensively studied. However, the highly symmetric and inert structure of CF4 makes it hard to be adsorbed on the catalyst surface. Herein, we developed a protonated sulfate (–HSO4) modified ZrO2 (S-ZrO2) to enhance CF4 adsorption and achieve its complete decomposition at 650 °C, which was superior to common γ-Al2O3. Combining the surface acidity test, in situ infrared spectroscopy and density function theory simulations, we demonstrated that the introduced –HSO4 effectively enhances the Lewis acidity of adjacent Zr sites, which shows strong CF4 adsorption ability and promotes its decomposition.
研究领域:
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2020
·Vol. 10
·期 3
·312
·
IF 3.52
Zhiwen Xi,Zhe Hong,Fangtao Huang,Zhirong Zhu,Wenzhi Jia,Junhui Li
A series of Pt/WOx-ZrO2-TiO2catalysts with different Ti/Zr molar ratios was prepared by an evaporation induced self-assembly method, and used to efficient hydrogenolysis of glycerol to 1-PO and 1,3-PDO. BET, XRD, Raman, TEM, XPS and Py-IR were employed to characterize the physicochemical properties of the catalysts. The structural and acidic properties of the catalysts were affected by the Ti/Zr ratio of the support ZrO2-TiO2. Two new crystalline phases of ZrTiO4and Ti2ZrO6and the amount of acid sites were detected in the Pt/WOx-ZrO2-TiO2catalysts. 1-PO is dominant in all products of glycerol hydrogenolysis over the supported Pt-WOx catalysts, which is attributed to more Lewis acid sites on the catalyst surface. The Pt/WOx-ZrO2-TiO2catalyst with a Ti/Zr ratio of 7/3 showed the highest 1,3-PDO yield (25.3%) and 1-PO yield (42.3%), due to its more acid sites including Brønsted and Lewis, and higher concentration of surface Pt0.Keywords:hydrogenolysis of glycerol;1,3-propanediol;1-propanediol;Pt-WOx;ZrO2-TiO2
研究领域:
催化化学
·
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Jingwei Chen,Xinqiang Wang,Yongshuai Xie,Shuying Shi,Guanghui Zhang,Luyi Zhu
Gd 2 Zr 2 O 7 /ZrO 2 (GZC) composite fibers were prepared by electro-spinning method. The XRD , XPS and Raman results showed that there were three crystalline phases, tetragonal phase ZrO 2 , cubic phase ZrO 2 and defect fluorite phase Gd 2 Zr 2 O 7 in GZC composite fibers. GZC fibers remained an intact fiber texture up to 1400 °C according to SEM photographs. The thermal conductivity of GZC fibers was between 0.173 W/(m·K) at 400 °C and 0.309 W/(m·K) at 800 °C, which was lower than that of 7YSZ under the same experimental conditions. The fiber sheet with density about 3.5 g/cm 3 has thermal shrinkage less than 3% at 1400 °C. Hence, GZC fibers could be used as refractories for heat protection.
研究领域:
材料科学
·
热能工程
✓ 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）