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Optimization of electrochemically synthesized Cu

Kasra Pirzadeh, Ali Asghar Ghoreyshi, Mostafa Rahimnejad, Maedeh Mohammadi

《化学科学与工程前沿（英文）》 2020年第14卷第2期页码 233-247 doi: 10.1007/s11705-019-1893-1

摘要： Cu (BTC) , a common type of metal organic framework (MOF), was synthesized through electrochemical route for CO capture and its separation from N . Taguchi method was employed for optimization of key parameters affecting the synthesis of Cu (BTC) . The results indicated that the optimum synthesis conditions with the highest CO selectivity can be obtained using 1 g of ligand, applied voltage of 25 V, synthesis time of 2 h, and electrode length of 3 cm. The single gas sorption capacity of the synthetized microstructure Cu (BTC) for CO (at 298 K and 1 bar) was a considerable value of 4.40 mmol·g . The isosteric heat of adsorption of both gases was calculated by inserting temperature-dependent form of Langmuir isotherm model in the Clausius-Clapeyron equation. The adsorption of CO /N binary mixture with a concentration ratio of 15/85 vol-% was also studied experimentally and the result was in a good agreement with the predicted value of IAST method. Moreover, Cu (BTC) showed no considerable loss in CO adsorption after six sequential cycles. In addition, artificial neural networks (ANNs) were also applied to predict the separation behavior of CO /N mixture by MOFs and the results revealed that ANNs could serve as an appropriate tool to predict the adsorptive selectivity of the binary gas mixture in the absence of experimental data.

关键词： Cu₃(BTC)₂ electrochemical synthesis CO₂ adsorption Taguchi optimization ANN modeling

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Preparation of Cu/ZnO/Al

Hui FAN, Huayan ZHENG, Zhong LI

《化学科学与工程前沿（英文）》 2010年第4卷第4期页码 445-451 doi: 10.1007/s11705-010-0521-x

摘要： Cu/ZnO/Al O catalysts with Cu/Zn/Al ratios of 6/3/1 were precipitated and aged by conventional and microwave heating methods and tested in the slurry phase reactor for methanol synthesis. The effect of technological condition of precipitation and aging process under microwave irradiation on the catalytic performance was investigated to optimize the preparing condition of Cu/ZnO/Al O catalyst. The results showed that the microwave irradiation during precipitation process could improve the activity of the catalyst, but had little effect on the stability. While the microwave irradiation during aging process has a great benefit to both the activity and stability of the catalyst, the catalyst aged at 80°C for 1 h under microwave irradiation possessed higher methanol space time yield (STY) and more stable catalytic activity. The activity and stability of the catalyst was further enhanced when microwave irradiation was used in both precipitation and aging processes; the optimized condition for the catalyst precursor preparation was precipitation at 60°C and aging at 80°C under microwave irradiation.

关键词： microwave irradiation precipitation temperature aging temperature methanol synthesis Cu/ZnO/Al₂O₃ catalyst

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Preparation of Cu/ZrO

Xinmei LIU, Shaofen BAI, Huidong ZHUANG, Zifeng YAN

《化学科学与工程前沿（英文）》 2012年第6卷第1期页码 47-52 doi: 10.1007/s11705-011-1170-4

摘要： Cu/ZrO catalysts for methanol synthesis from CO /H were respectively prepared by deposition coprecipitation (DP) and solid state reaction (SR) methods. There is an intimate interaction between copper and zirconia, which strongly affects the reduction property and catalytic performance of the catalysts. The stronger the interaction, the lower the reduction temperature and the better the performance of the catalysts. Surface area, pore structure and crystal structure of the catalysts are mainly controlled by preparation methods and alkalinity of synthesis system. The conversion of CO and selectivity of methanol are higher for DP catalysts than for SP catalysts.

关键词： Cu/ZrO₂ methanol synthesis deposition coprecipitation solid state reaction CO₂/H₂

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含稀释剂的Al-Cr2sub>O3sub>体系燃烧合成反应热力学分析与反应模型

张衍诚,潘冶,张传

《中国工程科学》 2004年第6卷第6期页码 63-67

摘要：

对含稀释剂Al203和Cr203的Al-Cr203体系燃烧合成反应进行了热力学计算与分析，讨论了起始反应温度T0、稀释剂Al2O3和Cr2O3的含量对绝热反应温度7^的影响，并得出T0与Tad在特定温度段上的近似线性关系以及该关系在指导材料成分设计上的应用；揭示了反应驱动力—&mdash

关键词：金属陶瓷燃烧合成 Al-Cr203体系热力学反应模型

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A Cu-modified active carbon fiber significantly promoted HS and PH simultaneous removal at a low reaction

《环境科学与工程前沿（英文）》 2021年第15卷第6期 doi: 10.1007/s11783-021-1425-3

摘要：

• Cu_0.15-ACF performs the best for H₂S and PH₃ simultaneous removal.

关键词： ACF H₂S PH₃ Cu Low temperature Simultaneous removal

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Rh2sub>O3sub>/hexagonal CePO4sub> nanocatalysts for N2sub>O decomposition

Huan Liu, Zhen Ma

《化学科学与工程前沿（英文）》 2017年第11卷第4期页码 586-593 doi: 10.1007/s11705-017-1659-6

摘要： Hexagonal CePO nanorods were prepared by a precipitation method and hexagonal CePO nanowires were prepared by hydrothermal synthesis at 150 °C. Rh(NO ) was then used as a precursor for the impregnation of Rh O onto these CePO materials. The Rh O supported on the CePO nanowires was much more active for the catalytic decomposition of N O than the Rh O supported on CePO nanorods. The stability of both catalysts as a function of time on stream was studied and the influence of the co-feed (CO , O , H O or O /H O) on the N O decomposition was also investigated. The samples were characterized by N adsorption-desorption, inductively coupled plasma optical emission spectroscopy, X-ray diffraction, transmission electron microscopy, X-ray photoelectron microscopy, hydrogen temperature-programmed reduction, oxygen temperature-programmed desorption, and CO temperature-programmed desorption in order to correlate the physicochemical and catalytic properties.

关键词： Rh₂O₃ CePO₄ N₂O decomposition

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Cu-doped Bi/Bi2sub>WO6sub> catalysts for efficient N2sub> fixation by photocatalysis

《化学科学与工程前沿（英文）》 2023年第17卷第10期页码 1412-1422 doi: 10.1007/s11705-023-2312-1

摘要： In this paper, Cu-doped Bi₂WO₆ was synthesized via a solvothermal method and applied it in photocatalytic N₂ immobilization. Characterization results showed the presence of a small amount of metallic Bi in the photocatalyst, indicating that the synthesized photocatalyst is actually Bi/Cu-Bi₂WO₆ composite. The doped Cu had a valence state of +2 and most likely substituted the position of Bi³⁺. The introduced Cu did not affect the metallic Bi content, but mainly influenced the energy band structure of Bi₂WO₆. The band gap was slightly narrowed, the conduction band was elevated, and the work function was reduced. The reduced work function improved the transfer and separation of charge carriers, which mainly caused the increased photoactivity. The optimized NH₃ generation rates of Bi/Cu-Bi₂WO₆ reached 624 and 243 μmol·L^–1·g^–1·h^–1 under simulated solar and visible light, and these values were approximately 2.8 and 5.9 times higher those of Bi/Bi₂WO₆, respectively. This research provides a method for improving the photocatalytic N₂ fixation and may provide more information on the design and preparation of heteroatom-doped semiconductor photocatalysts for N₂-to-NH₃ conversion.

关键词： Bi₂WO₆ Cu doping work function photocatalytic N₂ fixation charge separation

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Tuning the catalytic selectivity in electrochemical CO

Jiafang XIE,Yuxi HUANG,Hanqing YU

《环境科学与工程前沿（英文）》 2015年第9卷第5期页码 861-866 doi: 10.1007/s11783-014-0742-1

摘要： Electrochemical conversion of CO to hydrocarbons can relieve both environmental and energy stresses. However, electrocatalysts for this reaction usually suffer from a poor product selectivity and a large overpotential. Here we report that tunable catalytic selectivity for hydrocarbon formation could be achieved on Cu nanomaterials with different morphologies. By tuning the electrochemical parameters, either Cu oxide nanowires or nanoneedles were fabricated and then electrochemically reduced to the corresponding Cu nanomaterials. The Cu nanowires preferred the formation of C H , while the Cu nanoneedles favored the production of more CH , rather than C H . Our work provides a facile synthetic strategy for preparing Cu-based nanomaterials to achieve selective CO reduction.

关键词： electrochemical CO₂ reduction Cu oxide nanostructure selectivity hydrocarbon formation

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An investigation of the CHOH and CO selectivity of CO hydrogenation over Cu–Ce–Zr catalysts

《化学科学与工程前沿（英文）》 2022年第16卷第6期页码 950-962 doi: 10.1007/s11705-022-2162-2

摘要： A series of Cu–Ce–Zr catalysts with different Ce contents are applied to the hydrogenation of CO₂ to CO/CH₃OH products. The Cu–Ce–Zr catalyst with 2 wt% Ce loading shows higher CO selectivity (S_CO = 0.0%–87.8%) from 200–300 °C, while the Cu–Ce–Zr catalyst with 8 wt% Ce loading presents higher CO₂ conversion (

X C O 2

= 5.4%–15.6%) and CH₃OH selectivity (

S C H 3 O H

= 97.8%–40.6%). The number of hydroxyl groups and solid solution nature play a significant role in changing the reaction pathway. The solid solution enhances the CO₂ adsorption ability. At the CO₂ adsorption step, a larger number of hydroxyl groups over the Cu–Ce–Zr catalyst with 8 wt% Ce loading leads to the production of H-containing adsorption species. At the CO₂ hydrogenation step, a larger number of hydroxyl groups assists in encouraging the further hydrogenation of intermediate species to CH₃OH and improving the hydrogenation rate. Hence, the Cu–Ce–Zr catalyst with 8 wt% Ce loading favors CH₃OH selectivity and CO₂ activation, while CO is preferred on the Cu–Ce–Zr catalyst with 2 wt% Ce loading, a smaller number of hydroxyl groups and a solid solution nature. Additionally, high-pressure in situ diffuse reflectance infrared Fourier transform spectroscopy shows that CO is produced from formate decomposition and that both monodentate formate and bidentate formate are active intermediate species of CO₂ hydrogenation to CH₃OH.

关键词： CO₂ hydrogenation Cu–Ce–Zr hydroxyls CO/CH₃OH selectivity

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Advantageous mechanochemical synthesis of copper(I) selenide semiconductor, characterization, and properties

《化学科学与工程前沿（英文）》 2022年第16卷第3期页码 433-442 doi: 10.1007/s11705-021-2066-6

摘要： Copper(I) selenide-nanocrystalline semiconductor was synthesized via one-step mechanochemical synthesis after 5 min milling in a planetary ball mill. The kinetics of synthesis was followed by X-ray powder diffraction analysis and specific surface area measurements of milled 2Cu/Se mixtures. The X-ray diffraction confirmed the orthorhombic crystal structure of Cu₂Se with the crystallite size ~25 nm. The surface chemical structure was studied by X-ray photoelectron spectroscopy, whereby the binding energy of the Cu 2p and Se 3d signals corresponded to Cu⁺ and Se^2– oxidation states. Transmission electron microscopy revealed agglomerated nanocrystals and confirmed their orthorhombic structure, as well. The optical properties were studied utilizing ultraviolet-visible spectroscopy and photoluminescence spectroscopy. The direct bandgap energy 3.7 eV indicated a blue-shift phenomenon due to the quantum size effect. This type of Cu₂Se synthesis can be easily adapted to production dimensions using an industrial vibratory mill. The advantages of mechanochemical synthesis represent the potential for inexpensive, environmentally-friendly, and waste-free manufacturing of Cu₂Se.

关键词： Cu₂Se berzelianite nanocrystalline semiconductor mechanochemical synthesis planetary ball mill

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Ultrasound-assisted co-precipitation synthesis of mesoporous Co3O4–CeO2 composite oxides for highly selective

《化学科学与工程前沿（英文）》 2022年第16卷第8期页码 1211-1223 doi: 10.1007/s11705-022-2145-3

摘要： The one-step highly selective oxidation of cyclohexane into cyclohexanone and cyclohexanol as the essential intermediates of nylon-6 and nylon-66 is considerably challenging. Therefore, an efficient and low-cost catalyst must be urgently developed to improve the efficiency of this process. In this study, a Co₃O₄–CeO₂ composite oxide catalyst was successfully prepared through ultrasound-assisted co-precipitation. This catalyst exhibited a higher selectivity to KA-oil, which was benefited from the synergistic effects between Co³⁺/Co²⁺ and Ce⁴⁺/Ce³⁺ redox pairs, than bulk CeO₂ and/or Co₃O₄. Under the optimum reaction conditions, 89.6% selectivity to KA-oil with a cyclohexane conversion of 5.8% was achieved over Co₃O₄–CeO₂. Its catalytic performance remained unchanged after five runs. Using the synergistic effects between the redox pairs of different transition metals, this study provides a feasible strategy to design high-performance catalysts for the selective oxidation of alkanes.

关键词： Co₃O₄–CeO₂ composite oxides cyclohexanone cyclohexanol ultrasonic-assisted co-precipitation selective oxidation solvent-free

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Catalytic hydrolysis of gaseous HCN over Cu–Ni/γ-Al

Linxia Yan, Senlin Tian, Jian Zhou, Xin Yuan

《环境科学与工程前沿（英文）》 2016年第10卷第6期 doi: 10.1007/s11783-016-0872-8

摘要： ? The Cu–Ni/γ-Al O catalyst was prepared to study HCN hydrolysis ? On catalyst calcined at 400°C, the HCN removal efficiency reaches a maximum. ? HCN removal is the highest at 480 min at a H O/HCN volume ratio of 150 ? The presence of CO facilitates HCN hydrolysis and increases NH production. ? O increases the HCN removal and NO production but decreases NH production GRAPHIC ABSTRACT To decompose efficiently hydrogen cyanide (HCN) in exhaust gas, g-Al O -supported bimetallic-based Cu–Ni catalyst was prepared by incipient-wetness impregnation method. The effects of the calcination temperature, H O/HCN volume ratio, reaction temperature, and the presence of CO or O on the HCN removal efficiency on the Cu–Ni/g-Al O catalyst were investigated. To examine further the efficiency of HCN hydrolysis, degradation products were analyzed. The results indicate that the HCN removal efficiency increases and then decreases with increasing calcination temperature and H O/HCN volume ratio. On catalyst calcined at 400°C, the efficiency reaches a maximum close to 99% at 480 min at a H O/HCN volume ratio of 150. The HCN removal efficiency increases with increasing reaction temperature within the range of 100°C–500°C and reaches a maximum at 500°C. This trend may be attributed to the endothermicity of HCN hydrolysis; increasing the temperature favors HCN hydrolysis. However, the removal efficiencies increases very few at 500°C compared with that at 400°C. To conserve energy in industrial operations, 400°C is deemed as the optimal reaction temperature. The presence of CO facilitates HCN hydrolysis andincreases NH production. O substantially increases the HCN removal efficiency and NO production but decreases NH production.

关键词： Hydrogen cyanide Cu–Ni/g-Al₂O₃ Catalytic hydrolysis

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Events and reaction mechanisms during the synthesis of an Al

M. ABDELLAHI, M. ZAKERI, H. BAHMANPOUR

《化学科学与工程前沿（英文）》 2013年第7卷第2期页码 123-129 doi: 10.1007/s11705-013-1325-6

摘要： An Al O -TiB nanocomposite was successfully synthesized by the high energy ball milling of Al, B O and TiO . The structures of the powdered particles formed at different milling times were evaluated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Thermodynamic calculations showed that the composite formed in two steps via highly exothermic mechanically induced self-sustaining reactions (MSRs). The composite started to form at milling times of 9–10 h but the reaction was not complete. The remaining starting materials were consumed by increasing the milling time to 15 h. The XRD patterns of the annealed powders showed that aluminum borate is one of the intermediate products and that it is consumed at higher temperatures. Heat treatment of the 6-h milled sample at 1100 C led to a complete formation of the composite. Increasing the milling time to 15 h led to a refining of the crystallite sizes. A nanocomposite powder with a mean crystallite size of 35–40 nm was obtained after milling for 15 h.

关键词： ball milling nanocomposite Al₂O₃ TiB₂

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CO2sub> methanation and co-methanation of CO and CO2sub> over Mn-promoted Ni/Al2sub>O3sub> catalysts

Kechao Zhao,Zhenhua Li,Li Bian

《化学科学与工程前沿（英文）》 2016年第10卷第2期页码 273-280 doi: 10.1007/s11705-016-1563-5

摘要： A series of Mn-promoted 15 wt-% Ni/Al O catalysts were prepared by an incipient wetness impregnation method. The effect of the Mn content on the activity of the Ni/Al O catalysts for CO methanation and the co-methanation of CO and CO in a fixed-bed reactor was investigated. The catalysts were characterized by N physisorption, hydrogen temperature-programmed reduction and desorption, carbon dioxide temperature-programmed desorption, X-ray diffraction and high-resolution transmission electron microscopy. The presence of Mn increased the number of CO adsorption sites and inhibited Ni particle agglomeration due to improved Ni dispersion and weakened interactions between the nickel species and the support. The Mn-promoted 15 wt-% Ni/Al O catalysts had improved CO methanation activity especially at low temperatures (250 to 400 °C). The Mn content was varied from 0.86% to 2.54% and the best CO conversion was achieved with the 1.71Mn-Ni/Al O catalyst. The co-methanation tests on the 1.71Mn-Ni/Al O catalyst indicated that adding Mn markedly enhanced the CO methanation activity especially at low temperatures but it had little influence on the CO methanation performance. CO methanation was more sensitive to the reaction temperature and the space velocity than the CO methanation in the co-methanation process.

关键词： Mn promotion nickel catalysts CO₂ methanation co-methanation of CO and CO₂

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Investigation of fluorescence characterization and electrochemical behavior on the catalysts of nanosized

Chang-Mao HUNG, Wen-Liang LAI, Jane-Li LIN

《环境科学与工程前沿（英文）》 2013年第7卷第3期页码 428-434 doi: 10.1007/s11783-013-0517-0

摘要： This work describes the environmentally friendly technology for oxidation of ammonia (NH ) to form nitrogen at temperatures range from 423K to 673K by selective catalytic oxidation (SCO) over a nanosized Pt-Rh/γ-Al O catalyst prepared by the incipient wetness impregnation method of hexachloroplatinic acid (H PtCl ) and rhodium (III) nitrate (Rh(NO ) ) with γ-Al O in a tubular fixed-bed flow quartz reactor (TFBR). The characterization of catalysts were thoroughly measured using transmission electron microscopy (TEM), three-dimensional excitation-emission fluorescent matrix (EEFM) spectroscopy, UV-Vis absorption, dynamic light-scattering (DLS), zeta potential meter, and cyclic voltammetry (CV). The results demonstrated that at a temperature of 673K and an oxygen content of 4%, approximately 99% of the NH was removed by catalytic oxidation over the nanosized Pt-Rh/γ-Al O catalyst. N was the main product in NH -SCO process. Further, it reveals that the oxidation of NH was proceeds by the over-oxidation of NH into NO, which was conversely reacted with the NH to yield N . Therefore, the application of nanosized Pt-Rh/γ-Al O catalyst can significantly enhance the catalytic activity toward NH oxidation. One fluorescent peak for fresh catalyst was different with that of exhausted catalyst. It indicates that EEFM spectroscopy was proven to be an appropriate and effective method to characterize the Pt clusters in intrinsic emission from nanosized Pt-Rh/γ-Al O catalyst. Results obtained from the CV may explain the significant catalytic activity of the catalysts.

关键词： ammonia (NH₃) nanosized Pt-Rh/γ-Al₂O₃ catalyst excitation-emission fluorescent matrix (EEFM) selective catalytic oxidation (SCO) tubular fixed-bed reactor (TFBR)