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Cu(In 4

催化剂 4

Ga)Se₂ 3

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Promotional effect of ion-exchanged K on the low-temperature hydrothermal stability of Cu/SAPO-34 and

Chen Wang, Jun Wang, Jianqiang Wang, Meiqing Shen

《环境科学与工程前沿（英文）》 2021年第15卷第2期 doi: 10.1007/s11783-020-1322-1

摘要： Abstract • K+ hinder the structural degradation of Cu/SAPO-34 under humid condition<100°C. • K+ on Cu/SAPO-34 brings lower acidity and inferior SCR activity at high temperature. • Fe/Beta was used to compensate the low activity of Cu/SAPO-34 at high temperature. • The hybrid catalysts with KCu/SAPO-34 and Fe/Beta show a great potential for using. K ions were introduced onto Cu/SAPO-34 catalysts via the ion-exchange process in order to improve their stability under low-temperature hydrothermal aging. The changes in structure and copper-species contents of these catalysts upon hydrothermal aging were probed in order to investigate their effects on selective catalytic reduction (SCR) activity. For the fresh Cu/SAPO-34 catalysts, K ions had little influence on the chabazite framework but effected their acidities by exchanging with acid sites. After hydrothermal aging, the structural integrity and amount of active sites decreased on pure Cu/SAPO-34. While the K-loaded catalysts showed improved chabazite structure, acidity, and active site conservation with increasing K loading. However, although the 0.7 wt% K catalyst maintained the same crystallinity, active site abundance, and low-temperature SCR activity as the fresh catalyst upon aging, an apparent decrease in SCR activity at high temperature was observed because of the inevitable decrease in the number of Brönsted acid sites. To compensate for the activity disadvantage of K-loaded Cu/SAPO-34 at high temperature, Fe/Beta catalysts were co-employed with K-loaded Cu/SAPO-34, and a wide active temperature window of SCR activity was obtained. Thus, our study reveals that a combined system comprising Fe/Beta and K-loaded Cu/SAPO-34 catalysts shows promise for the elimination of NOx in real-world applications.

关键词： Selective catalytic reduction Cu/SAPO-34 catalyst Ion-exchanged K Low-temperature hydrothermal stability Fe/Beta catalyst

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Kinetic study of the methanol to olefin process on a SAPO-34 catalyst

Mehdi SEDIGHI,Kamyar KEYVANLOO

《化学科学与工程前沿（英文）》 2014年第8卷第3期页码 306-311 doi: 10.1007/s11705-014-1440-z

摘要： In this paper, a new kinetic model for methanol to olefin process over SAPO-34 catalyst was developed using elementary step level. The kinetic model fits well to the experimental data obtained in a fixed bed reactor. Using this kinetic model, the effect of the most important operating conditions such as temperature, pressure and methanol space-time on the product distribution has been examined. It is shown that the temperature ranges between 400 °C and 450 °C is appropriate for propene production while the medium temperature (450 °C) is favorable for total olefin yield which is equal to 33%. Increasing the reactor pressure decreases the ethylene yield, while medium pressure is favorable for the propylene yield. The result shows that the ethylene and propylene and consequently the yield of total olefins increase to approximately 35% with decreasing the molar ratio of inlet water to methanol.

关键词： methanol to olefin SAPO-34 kinetic modeling elementary step

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Effect of temperature in the conversion of methanol to olefins (MTO) using an extruded SAPO-34 catalyst

Ignacio Jorge Castellanos-Beltran, Gnouyaro Palla Assima, Jean-Michel Lavoie

《化学科学与工程前沿（英文）》 2018年第12卷第2期页码 226-238 doi: 10.1007/s11705-018-1709-8

摘要： The methanol-to-olefin (MTO) reaction was investigated in a bench-scale, fixed-bed reactor using an extruded catalyst composed of a commercial SAPO-34 (65 weight percentage, wt-%) embedded in an amorphous SiO matrix (35 wt-%). The texture properties, acidity and crystal structure of the pure SAPO-34 and its extruded form (E-SAPO-34) were analyzed and results indicated that the extrusion step did not affect the properties of the catalyst. Subsequently, E-SAPO-34 was tested in a temperature range between 300 and 500 °C, using an aqueous methanol mixture (80 wt-% water content) fed at a weight hour space velocity (WHSV) of 1.21 h . At 300 °C, a low conversion was observed combined with catalyst deactivation, which was ascribed to oligomerization and condensation reactions. The coke analysis showed the presence of diamandoid hydrocarbons, which are known to be inactive molecules in the MTO process. At higher temperatures, a quasi-steady state was reached during a 6 h reaction where the optimal temperature was identified at 450 °C, which incidentally led to the lowest coke deposition combined with the highest H/C ratio. Above 450 °C, surges of ethylene and methane were associated to a combination of H-transfer and protolytic cracking reactions. Finally, the present work underscored the convenience of the extrusion technique for testing catalysts at simulated scale-up conditions.

关键词： MTO SAPO-34 temperature extrusion coke light alkanes

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High-precision diffusion measurement of ethane and propane over SAPO-34 zeolites for methanol-to-olefin

Dali Cai, Yu Cui, Zhao Jia, Yao Wang, Fei Wei

《化学科学与工程前沿（英文）》 2018年第12卷第1期页码 77-82 doi: 10.1007/s11705-017-1684-5

摘要： The methanol-to-olefin (MTO) process has attracted much attention and many problems including lifetime and selectivity of light olefins have all been connected to the diffusion problems in zeolite crystals. However, a quantitative study of diffusion problems in SAPO-34 zeolites is lacking. In this paper, we performed a high-precision diffusion measurement of the diffusion behavior of ethane and propane, which represent ethylene and propylene respectively, over SAPO-34. The diffusions of ethane and propane over fresh and coked SAPO-34 zeolites with different crystal sizes were carefully studied. Ethane and propane show different diffusion behavior in SAPO-34. The diffusion of ethane is almost not influenced by the crystal size and coke percentage, whereas that of propane is strongly affected. A slower diffusion velocity was observed in bigger crystals, and the diffusion velocity decline significantly with the coke percentage increasing. The diffusion coefficient was calculated with both the internal and surface diffusion models, and the results show that the surface diffusion plays a key role in the diffusion process of both ethane and propane. We believe that this work would be helpful for understanding the diffusion of different molecules in SAPO-34 zeolites, and may lay the foundation of MTO research.

关键词： diffusion measurement methanol-to-olefin process

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Effect of SiO

Qian WANG, Lei WANG, Hui WANG, Zengxi LI, Xiangping ZHANG, Suojiang ZHANG, Kebin ZHOU

《化学科学与工程前沿（英文）》 2011年第5卷第1期页码 79-88 doi: 10.1007/s11705-010-0550-5

摘要： A series of SAPO-34 molecular sieves with different SiO /Al O ratios have been synthesized for the methanol-to-olefin (MTO) reaction. Their physico-chemical properties are characterized by various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR) and N adsorption-desorption. The results are compared with those of the commercial HZSM-5, which show that the crystallinity and particle diameter of SAPO-34 as well as HZSM-5 increase with SiO /Al O ratio. The variation of BET surface area of SAPO-34 is different from that of HZSM-5 and the sample with SiO /Al O ratio of 0.4 exhibits the highest BET surface area. FT-IR spectra indicate that HZSM-5 has both Br?nsted and Lewis acid sites and Br?nsted acid sites are stronger, whereas SAPO-34 samples are dominated only by Lewis acid sites. When the SiO /Al O ratio increases, propylene and butylenes become the predominant product of the MTO reaction over HZSM-5. In contrast, the main products of this reaction catalyzed by SAPO-34 are ethylene and propylene. According to the product distribution, the reaction mechanism over HZSM-5 catalysts is proposed.

关键词： HZSM-5 SAPO-34 methanol-to-olefin (MTO) SiO₂/Al₂O₃ ratio

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Reconstruction of Cu–ZnO catalyst by organic acid and deactivation mechanism in liquid-phase hydrogenation

《化学科学与工程前沿（英文）》 2023年第17卷第9期页码 1311-1319 doi: 10.1007/s11705-022-2281-9

摘要： A reconstructed Cu–ZnO catalyst with improved stability was fabricated by organic acid treatment method for the liquid-phase hydrogenation of dimethyl succinate to 1,4-butanediol. According to the characterization results of the fresh Cu–ZnO and reconstructed Cu–ZnO, three different forms of ZnO were suggested to be presented on the catalysts: ZnO having strong interaction with Cu species, ZnO that weakly interacted with Cu species and isolated ZnO. The first form of ZnO was believed to be beneficial to the formation of efficient active site Cu⁺, while the latter two forms of ZnO took the main responsibility for the deactivation of Cu–ZnO catalysts in the liquid-phase hydrogenation of diesters. The reconstruction of the Cu–ZnO catalyst by the organic acid treatment method resulted in a new Cu–ZnO catalyst with more Cu⁺ and less ZnO species that leads to deactivation. Furthermore, the deactivation mechanism of Cu–ZnO catalysts in liquid-phase diester hydrogenation in continuous flow system was proposed: the deposition of the polyesters on the catalysts via transesterification catalyzed by weakly interacted ZnO and isolated ZnO leads to the deactivation. These results provided meaningful instructions for designing highly efficient Cu–Zn catalysts for similar ester hydrogenation systems.

关键词： liquid phase hydrogenation Cu–ZnO deactivation mechanism 1 4-butanediol diester

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V-W-Mo-Cu催化剂作用下生物质醇解重油加氢精制研究

邹献武,秦特夫,李改云,黄洛华

《中国工程科学》 2014年第16卷第4期页码 69-73

摘要：为此，本文考察了V-W-Mo-Cu 催化剂作用下重油的加氢精制。结果表明，在330 ℃以上该催化剂才表现出加氢反应活性，在450 ℃时轻油产率最高可到93 %。

关键词：生物质醇解重油加氢 V-W-Mo-Cu催化剂图像处理

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Efficient and selective electro-reduction of nitrobenzene by the nano-structured Cu catalyst prepared

Yali CHEN,Lu XIONG,Weikang WANG,Xing ZHANG,Hanqing YU

《环境科学与工程前沿（英文）》 2015年第9卷第5期页码 897-904 doi: 10.1007/s11783-015-0782-1

摘要： Pollution caused by toxic nitrobenzene has been a widespread environmental concern. Selective reduction of nitrobenzene to aniline is beneficial to further efficient and cost-effective biologic treatment. Electrochemical reduction is a promising method and Cu-based catalysts have been found to be an efficient cathode material for this purpose. In this work, Cu catalysts with different morphologies were fabricated on Ti plate using a facile electrodepositon method via tuning the applied voltage. The dendritic nano-structured Cu catalysts obtained at high applied voltages exhibited an excellent efficiency and selectivity toward the reduction of nitrobenzene to aniline. Effects of the working potential and initial nitrobenzene concentration on the selective reduction of nitrobenzene to aniline using the Cu/Ti electrode were investigated. A high rate constant of 0.0251 min and 97.1% aniline selectivity were achieved. The fabricated nano-structured Cu catalysts also exhibited good stability. This work provides a facile way to prepare highly efficient, cost-effective, and stable nano-structured electrocatalysts for pollutant reduction.

关键词： nitrobenzene nano-structured Cu electro-reduction voltage-dependent electrodeposition high selectivity high stability

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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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NO hydrogenation to NH over FeCu/TiO catalyst with improved activity

《化学科学与工程前沿（英文）》 2023年第17卷第12期页码 1973-1985 doi: 10.1007/s11705-023-2364-2

摘要： Ammonia is crucial in industry and agriculture, but its production is hindered by environmental concerns and energy-intensive processes. Hence, developing an efficient and environmentally friendly catalyst is imperative. In this study, we employed a straightforward and efficient impregnation technique to create various Cu-doped catalysts. Notably, the optimized 10Fe-8Cu/TiO₂ catalyst exhibited exceptional catalytic performance in converting NO to NH₃, achieving an NO conversion rate exceeding 80% and an NH₃ selectivity exceeding 98% at atmospheric pressure and 350 °C. We employed in situ diffuse reflectance Fourier transform infrared spectroscopy and conducted density functional theory calculations to investigate the intermediates and subsequent adsorption. Our findings unequivocally demonstrate that Cu doping enhances the rate-limiting hydrogenation step and lowers the energy barrier for NH₃ desorption, thereby resulting in improved NO conversion and enhanced selectivity toward ammonia. This study presents a pioneering approach toward energy-efficient ammonia synthesis and recycling of nitrogen sources.

关键词： NO hydrogenation synthetic ammonia 10Fe-xCu/TiO₂ high selectivity

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Mechanistic understanding of Cu-based bimetallic catalysts

You Han, Yulian Wang, Tengzhou Ma, Wei Li, Jinli Zhang, Minhua Zhang

《化学科学与工程前沿（英文）》 2020年第14卷第5期页码 689-748 doi: 10.1007/s11705-019-1902-4

摘要： Copper has received extensive attention in the field of catalysis due to its rich natural reserves, low cost, and superior catalytic performance. Herein, we reviewed two modification mechanisms of co-catalyst on the coordination environment change of Cu-based catalysts: (1) change the electronic orbitals and geometric structure of Cu without any catalytic functions; (2) act as an additional active site with a certain catalytic function, as well as their catalytic mechanism in major reactions, including the hydrogenation to alcohols, dehydrogenation of alcohols, water gas shift reaction, reduction of nitrogenous compounds, electrocatalysis and others. The influencing mechanisms of different types of auxiliary metals on the structure-activity relationship of Cu-based catalysts in these reactions were especially summarized and discussed. The mechanistic understanding can provide significant guidance for the design and controllable synthesis of novel Cu-based catalysts used in many industrial reactions.

关键词： copper bimetallic catalyst coordination modification mechanism catalytic application

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Effects of the SAPO-11 synthetic process on dehydration of ethanol to ethylene

Lina WU, Xiaoxing SHI, Qun CUI, Haiyan WANG, He HUANG

《化学科学与工程前沿（英文）》 2011年第5卷第1期页码 60-66 doi: 10.1007/s11705-010-0540-7

摘要： The effects of the synthetic condition of SAPO-11 molecular sieves on ethanol dehydration to ethylene were studied. Product-compositions, ethanol conversion, and selectivity to ethylene of synthesized and commercial SAPO-11 molecular sieves were compared. Results are as follows: the optimal synthetic conditions for SAPO-11 molecular sieves are adding pseudoboehmite before orthophoshporic, using di-n- propylamine as the template, having a mass fraction of 40% colloidal silica as the silica source and the starting gel obtained, and running at 200°C for 48 h. From the patterns of NH -TPD, the amount of acid synthesized by SAPO-11 molecular sieves is less than that by commercial SAPO-11 molecular sieves, and has a stronger weak acid. Also, ethanol conversion and selectivity to ethylene reached 99% at 280°C on synthesized SAPO-11, lower by 20°C compared to commercial SAPO-11. For two SAPO-11 molecular sieves, the by-products in the gas phase are mainly ethane, propane, propene, isobutane, n-butane, propadiene, butylene and some higher hydrocarbons. The by-products in the liquid phase are ethyl ether and acetaldehyde.

关键词： SAPO-11 molecular sieves synthesis ethanol ethylene dehydration

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Correlative investigation of copper/low-density polyethylene nanocomposite on the endometrial angiogenesis in rats

LI Jianxiong, LIU Zilong, DUAN Yonggang, YU Jing, ZHU Changhong, LI Shuang, XIE Changsheng

《医学前沿（英文）》 2007年第1卷第4期页码 401-404 doi: 10.1007/s11684-007-0078-3

摘要： The purpose of this study was to investigate the effects of copper/low-density polyethylene nanocomposite (nano-Cu/LDPE) on the endometrial angiogenesis in rats, and 100 sexual mature female SD rats were randomly divided into five groups: sham-operation groups (SO group, = 20), bulk copper groups (Cu group, = 20), LDPE groups ( = 20), nano-Cu/LDPE groups I ( = 20) and II ( = 20). The levels of angiopoietin-2 (Ang-2), its receptor (Tie-2) and CD34 of the rats endometria in each group were examined by using the S-P method of the immunohistochemistry 30 and 180 days after insertion, respectively. Compared with those in the SO group, the expression of Ang-2 and Tie-2 in all the experimental groups was obviously increased 30 days after insertion, and these parameters in nano-Cu/LDPE groups, except for Ang-2 level in nano-Cu/LDPE group II, were significantly lower in comparison with those in Cu group (<0.05). On the 180th day after insertion, Ang-2 and Tie-2 levels were still higher in Cu group and LDPE group, but there was no difference of Ang-2 and Tie-2 levels between nano-Cu/LDPE groups and the SO group (>0.05). Compared with those in the SO group, the significant increases in microvessel density (MVD) were observed on the 30th and the 180th day after the insertion of the bulk copper (<0.05). There was no significant difference in MVD counts before and after the insertion of nano-Cu/LDPE (>0.05). The results show that Nano-Cu/LDPE have slighter influence on the endometrial angiogenesis than bulk copper.

关键词： significant difference female endometrial angiogenesis nano-Cu/LDPE CD34

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Clinical significance of CD34⁺CD117^dim/CD34⁺CD117^bri myeloblast-associated

Xueping Li, Yuting Dai, Bing Chen, Jinyan Huang, Saijuan Chen, Lu Jiang

《医学前沿（英文）》 2021年第15卷第4期页码 608-620 doi: 10.1007/s11684-021-0836-7

摘要： t(8;21)(q22;q22) acute myeloid leukemia (AML) is a highly heterogeneous hematological malignancy with a high relapse rate in China. Two leukemic myeloblast populations (CD34 CD117 and CD34 CD117 ) were previously identified in t(8;21) AML, and CD34 CD117 cell proportion was determined as an independent factor for this disease outcome. Here, we examined the impact of CD34 CD117 /CD34 CD117 myeloblast-associated gene expression on t(8;21) AML clinical prognosis. In this study, 85 patients with t(8;21) AML were enrolled. The mRNA expression levels of CD34 CD117 -associated genes ( , , and ) and CD34 CD117 -associated genes ( , , and ) were measured using quantitative reverse transcription PCR. Associations between gene expression and clinical outcomes were determined using Cox regression models. Results showed that patients with high , , or expression had significantly inferior overall survival (OS), whereas those with high or expression showed relatively favorable prognosis. Univariate analysis revealed that CD19, CD34 CD117 proportion, mutation, minimal residual disease (MRD), and expression levels of , , , and were associated with OS. Multivariate analysis indicated that mutation, MRD and and expression levels were independent prognostic variables for OS. Identifying the clinical relevance of CD34 CD117 /CD34 CD117 myeloblast-associated gene expression may provide new clinically prognostic markers for t(8;21) AML.

关键词： t(8 21)(q22 q22) AML CD34⁺CD117^dim/ CD34⁺CD117^bri cell population gene expression prognosis

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Investigation of the preparation methodologies of Pd-Cu single atom alloy catalysts for selective hydrogenation

Xinxiang Cao,Arash Mirjalili,James Wheeler,Wentao Xie,Ben W.-L. Jang

《化学科学与工程前沿（英文）》 2015年第9卷第4期页码 442-449 doi: 10.1007/s11705-015-1547-x

摘要： Galvanic replacement, co-impregnation and sequential impregnation have been employed to prepare Pd-Cu bimetallic catalysts with less than 1 wt-% Cu and ca. 0.03 wt-% Pd for selective hydrogenation of acetylene in excess ethylene. High angle annular dark field-scanning transmission electron microscopy (HAADF-STEM) and H chemisorption results confirmed that Pd-Cu single-atom alloy structures were constructed in all three bimetallic catalysts. Catalytic tests indicated that when the conversion of acetylene was above 99%, the selectivity of ethylene of these three single atom alloy catalysts was still more than 73%. Furthermore, the single atom alloy catalyst prepared by sequential incipient wetness impregnation was found to have the best stability among the three procedures used.

关键词： H₂ pulse chemisorption palladium-copper bimetallic catalyst single atom alloy acetylene hydrogenation HAADF-STEM