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期刊论文 30

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PIC16F877A 1

RS—485总线 1

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单价选择性阳离子交换膜 1

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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    

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 (SCO = 0.0%–87.8%) from 200–300 °C, while the Cu–Ce–Zr catalyst with 8 wt% Ce loading presents higher CO2 conversion ( XCO2 = 5.4%–15.6%) and CH3OH selectivity ( SCH3OH = 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    

Solar fuel from photo-thermal catalytic reactions with spectrum-selectivity: a review

Sanli TANG, Jie SUN, Hui HONG, Qibin LIU

《能源前沿(英文)》 2017年 第11卷 第4期   页码 437-451 doi: 10.1007/s11708-017-0509-z

摘要: Solar fuel is one of the ideal energy sources in the future. The synergy of photo and thermal effects leads to a new approach to higher solar fuel production under relatively mild conditions. This paper reviews different approaches for solar fuel production from spectrum-selective photo-thermal synergetic catalysis. The review begins with the meaning of synergetic effects, and the mechanisms of spectrum-selectivity and photo-thermal catalysis. Then, from a technical perspective, a number of experimental or theoretical works are sorted by the chemical reactions and the sacrificial reagents applied. In addition, these works are summarized and tabulated based on the operating conditions, spectrum-selectivity, materials, and productivity. A discussion is finally presented concerning future development of photo-thermal catalytic reactions with spectrum-selectivity.

关键词: photo-thermal catalysis     spectrum-selectivity     solar fuel     full-spectrum    

Enhancing the aromatic selectivity of cyclohexane aromatization by CO2 coupling

《化学科学与工程前沿(英文)》 2023年 第17卷 第11期   页码 1801-1808 doi: 10.1007/s11705-023-2325-9

摘要: Improving the aromatic selectivity in the alkane aromatization process is of great importance for its practical utilization but challenge to make because the high H/C ratio of alkanes would lead to a serious hydrogen transfer process and a large amount of light alkanes. Herein, CO2 is introduced into the cyclohexane conversion process on the HZSM-5 zeolite, which can improve the aromatic selectivity. By optimizing the reaction conditions, an improved aromatic (benzene, toluene, xylene, and C9+) selectivity of 48.2% can be obtained at the conditions of 2.7 MPa (CO2), 450 °C, and 1.7 h−1, which is better than that without CO2 (aromatic selectivity = 43.2%). In situ transmission Fourier transform infrared spectroscopy spectra illustrate that many oxygenated chemical intermediates (e.g., carboxylic acid, anhydride, unsaturated aldehydes/ketones or ketene) would be formed during the cyclohexane conversion process in the presence of CO2. 13C isotope labeling experimental results demonstrate that CO2 can enter into the aromatics through the formation of oxygenated chemical intermediates and thereby improve the aromatic selectivity. This study may open a green, economic, and promising way to improve the aromatic selectivity for alkane aromatization process.

关键词: aromatics     carbon dioxide     aromatization     coupling reaction     ZSM-5 zeolite    

Non-toxic, high selectivity process for the extraction of precious metals from waste printed circuit

《环境科学与工程前沿(英文)》 2023年 第17卷 第10期 doi: 10.1007/s11783-023-1723-z

摘要:

● Au, Ag and Pd were recovered from WPCBs with high efficiencies.

关键词: Thiosulfate     Printed circuit boards     Precious metals     Leaching     Hydrometallurgy    

Catalysis of semihydrogenation of acetylene to ethylene: current trends, challenges, and outlook

《化学科学与工程前沿(英文)》 2022年 第16卷 第7期   页码 1031-1059 doi: 10.1007/s11705-021-2113-3

摘要: Ethylene is an important feedstock for various industrial processes, particularly in the polymer industry. Unfortunately, during naphtha cracking to produce ethylene, there are instances of acetylene presence in the product stream, which poisons the Ziegler–Natta polymerization catalysts. Thus, appropriate process modification, optimization, and in particular, catalyst design are essential to ensure the production of highly pure ethylene that is suitable as a feedstock in polymerization reactions. Accordingly, carefully selected process parameters and the application of various catalyst systems have been optimized for this purpose. This review provides a holistic view of the recent reports on the selective hydrogenation of acetylene. Previously published reviews were limited to Pd catalysts. However, effective new metal and non-metal catalysts have been explored for selective acetylene hydrogenation. Updates on this recent progress and more comprehensive computational studies that are now available for the reaction are described herein. In addition to the favored Pd catalysts, other catalyst systems including mono, bimetallic, trimetallic, and ionic catalysts are presented. The specific role(s) that each process parameter plays to achieve high acetylene conversion and ethylene selectivity is discussed. Attempts have been made to elucidate the possible catalyst deactivation mechanisms involved in the reaction. Extensive reports suggest that acetylene adsorption occurs through an active single-site mechanism rather than via dual active sites. An increase in the reaction temperature affords high acetylene conversion and ethylene selectivity to obtain reactant streams free of ethylene. Conflicting findings to this trend have reported the presence of ethylene in the feed stream. This review will serve as a useful resource of condensed information for researchers in the field of acetylene-selective hydrogenation.

关键词: selectivity     hydrogenation     acetylene     ethylene     palladium    

Transport and selectivity of indium through polymer inclusion membrane in hydrochloric acid medium

Xiaorong Meng, Conghui Wang, Pan Zhou, Xiaoqiang Xin, Lei Wang

《环境科学与工程前沿(英文)》 2017年 第11卷 第6期 doi: 10.1007/s11783-017-0950-6

摘要: In the present paper, a polymer inclusion membrane (PIM) containing polyvinyl chloride (PVC), and bis-(2-ethylhexyl) phosphate (D2EHPA) which was used as extracting agent was used for the recovery of In(III) ions in hydrochloric acid medium. The effects of carrier concentration, feed phase pH, strip phase HCl concentration, temperature on the transport, and the membrane’s stability and thickness were examined. And the conditions for the selective separation of In(III) and Cu(II) were optimized. The results showed that the transport of In(III) across PIM was consistent with the first order kinetics equation, and also it was controlled by both the diffusion of the metal complex in the membrane and the chemical reaction at the interface of the boundary layers. The transport flux ( ) was inversely proportional to the membrane thickness, however, the transport stability improved as the membrane thickness increased. The transport flux of In(III) and Cu(II) was decreased by excessive acidity of feed phase and high concentration of Cl . The selectivity separation coefficient of In(III)/Cu(II) was up to 34.33 when the original concentration of both In(III) and Cu(II) was 80 mg·L as well as the pH of the feed phase and the concentration of Cl in the adjusting context were0.6 and 0.5 mol·L , respectively. Within the range of pH= 1–3, the separation selectivity of In(III)/Cu(II) reached the peak in the case when the Cl concentration was 0.7 mol·L .

关键词: Polymer inclusion membrane     Selective transport     D2EHPA     In(III)     Cu(II)    

Nanofiltration for drinking water treatment: a review

《化学科学与工程前沿(英文)》 2022年 第16卷 第5期   页码 681-698 doi: 10.1007/s11705-021-2103-5

摘要: In recent decades, nanofiltration (NF) is considered as a promising separation technique to produce drinking water from different types of water source. In this paper, we comprehensively reviewed the progress of NF-based drinking water treatment, through summarizing the development of materials/fabrication and applications of NF membranes in various scenarios including surface water treatment, groundwater treatment, water reuse, brackish water treatment, and point of use applications. We not only summarized the removal of target major pollutants (e.g., hardness, pathogen, and natural organic matter), but also paid attention to the removal of micropollutants of major concern (e.g., disinfection byproducts, per- and polyfluoroalkyl substances, and arsenic). We highlighted that, for different applications, fit-for-purpose design is needed to improve the separation capability for target compounds of NF membranes in addition to their removal of salts. Outlook and perspectives on membrane fouling control, chlorine resistance, integrity, and selectivity are also discussed to provide potential insights for future development of high-efficiency NF membranes for stable and reliable drinking water treatment.

关键词: nanofiltration     drinking water     disinfection byproducts     micropollutants     selectivity    

Adsorption selectivity of salicylic acid and 5-sulfosalicylic acid onto hypercrosslinked polymeric adsorbents

LIU Fuqiang, CHEN Jinlong, LI Aimin, XIA Mingfang, FEI Zhenghao

《环境科学与工程前沿(英文)》 2007年 第1卷 第1期   页码 73-78 doi: 10.1007/s11783-007-0014-4

摘要: Both bottle-point and column-feeding experiments involving different solutes and sorbents were carried out to investigate the adsorption selectivity and separation performance of salicylic acid and 5-sulfosalicylic acid. Their adsorption isotherms onto such hypercrosslinked polymeric adsorbents as NDA-100 and NDA-99 could be well described by the Freundlich equations whose characteristics describe extrathermic and favorable adsorption processes. The adsorption towards NDA-100 mainly depended on the π-π interaction, while that towards NDA-99 was extremely influenced by the static-electric interaction. Additionally, the adsorptive capacity of salicylic acid on NDA-99 decreased while it increased on NDA-100 with the presence of 5-sulfosalicylic acid in the adsorptive environment as the competitive component. Comparatively, the adsorption capacity of 5-sulfosalicylic acid decreased on both resins with salicylic acid as the competitive component. In fact, the difference in the interaction between adsorbent and adsorbate resulted in the straight antagonism on the effective adsorption sites on the adsorbent. In conclusion, the adsorption selectivity of salicylic acid onto NDA-100 was obviously larger than that onto NDA-99 with the existence of 5-sulfosalicylic acid in the adsorptive environment. A satisfactory separation and recovery of tested solutes in aqueous phase could be foreseeably achieved by the sequencing adsorption technique involving NDA-100 as well as NDA-99.

关键词: 5-sulfosalicylic     bottle-point     hypercrosslinked polymeric     satisfactory separation     NDA-100    

Selective oxidation of o -nitrotoluene to o -nitrobenzaldehyde with metalloporphyrins as biomimetic catalysts

Xinling WANG, Yuanbin SHE,

《化学科学与工程前沿(英文)》 2009年 第3卷 第4期   页码 453-456 doi: 10.1007/s11705-009-0167-8

摘要: Selective oxidation of -nitrotoluene to -nitrobenzaldehyde with metalloporphyrins as biomimetic catalysts was studied. The peripheral substituent around porphyrin rings and various process parameters of NaOH concentration, reaction temperature, reaction time and oxygen pressure all affect the selectivity of -nitrobenzaldehyde. Further, 82.0% selectivity of -nitrobenzaldehyde was achieved under the optimum conditions: 1.0×10mol•L of T(-NO)PPFeCl catalyst, 2.5mol•L of NaOH, 0.2mol•L of -nitrotoluene, 45°C and 2.0MPa for 6h.

关键词: -nitrobenzaldehyde     temperature     biomimetic     selectivity     pressure    

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    

Advancing ion-exchange membranes to ion-selective membranes: principles, status, and opportunities

《环境科学与工程前沿(英文)》 2023年 第17卷 第2期 doi: 10.1007/s11783-023-1625-0

摘要:

● IEM ion/ion selectivities of charge, valence, & specific ion are critically assessed.

关键词: Ion-exchange membranes     Selectivity     Separations    

Effective and selective separation of perrhenate from acidic wastewater by super-stable, superhydrophobic, and recyclable biosorbent

《环境科学与工程前沿(英文)》 2022年 第16卷 第2期 doi: 10.1007/s11783-021-1456-9

摘要:

• A ZnO-biochar hybrid composite was prepared by solvothermal-pyrolysis synthesis.

关键词: Selectivity     Adsorption     Re(VII)     ZnO     Biochar    

矿井低压电网选择性漏电保护系统总体设计与实现

孙玉坤,朱志莹,黄振跃,唐平

《中国工程科学》 2012年 第14卷 第7期   页码 93-97

摘要:

设计了一款以dsPIC30F4012为主控制器、PIC16F877A为从处理器的新型主从式选择性漏电保护系统。该系统在总开关处采用附加直流源检测原理检测是否发生漏电,在分支开关处使用零序功率方向检测原理判断发生漏电故障线路,给出了保护系统的硬件框图和软件流程图,并且采用速度更快的RS—485总线及光纤传输技术,实现了矿井低压电网漏电保护的瞬动性。实验结果验证了该保护系统的优越性能。

关键词: 漏电保护     选择性     dsPIC30F4012     PIC16F877A     RS—485总线     光纤通信    

Extractive desulfurization of model fuels with a nitrogen-containing heterocyclic ionic liquid

《化学科学与工程前沿(英文)》 2022年 第16卷 第12期   页码 1735-1742 doi: 10.1007/s11705-022-2167-x

摘要: A nitrogen-containing ionic liquid was synthesized using an aromatic nitrogen-containing heterocyclic and an amino acid, and applied to the extractive desulfurization process to remove benzothiophene, dibenzothiophene, and 4,6-dimethyldibenzothiphene from a model fuel oil. Chemical characterizations and simulation using Gaussian 09 software confirmed the rationality of an ionic liquid structure. Classification of non-covalent interactions between the ionic liquid and the three sulfur-containing contaminants was studied by reduced density gradient analysis. The viscosity of the ionic liquid was adjusted by addition of polyethylene glycol. Under extraction conditions of the volume of ionic liquid to oil as 1:1 and temperature as room temperature, the desulfurization selectivity of ionic liquid followed the order of 4,6-dimethyldibenzothiphene (15 min) < benzothiophene (15 min) ≈ dibenzothiophene (10 min). Addition of p-xylene and cyclohexene to the fuel oil had little effect. The extractant remained stable and effective after multiple regeneration cycles.

关键词: extractive desulfurization     nitrogen-containing heterocyclic ionic liquid     reduced density gradient analysis     desulfurization selectivity    

标题 作者 时间 类型 操作

Tuning the catalytic selectivity in electrochemical CO

Jiafang XIE,Yuxi HUANG,Hanqing YU

期刊论文

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

期刊论文

Solar fuel from photo-thermal catalytic reactions with spectrum-selectivity: a review

Sanli TANG, Jie SUN, Hui HONG, Qibin LIU

期刊论文

Enhancing the aromatic selectivity of cyclohexane aromatization by CO2 coupling

期刊论文

Non-toxic, high selectivity process for the extraction of precious metals from waste printed circuit

期刊论文

Catalysis of semihydrogenation of acetylene to ethylene: current trends, challenges, and outlook

期刊论文

Transport and selectivity of indium through polymer inclusion membrane in hydrochloric acid medium

Xiaorong Meng, Conghui Wang, Pan Zhou, Xiaoqiang Xin, Lei Wang

期刊论文

Nanofiltration for drinking water treatment: a review

期刊论文

Adsorption selectivity of salicylic acid and 5-sulfosalicylic acid onto hypercrosslinked polymeric adsorbents

LIU Fuqiang, CHEN Jinlong, LI Aimin, XIA Mingfang, FEI Zhenghao

期刊论文

Selective oxidation of o -nitrotoluene to o -nitrobenzaldehyde with metalloporphyrins as biomimetic catalysts

Xinling WANG, Yuanbin SHE,

期刊论文

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

期刊论文

Advancing ion-exchange membranes to ion-selective membranes: principles, status, and opportunities

期刊论文

Effective and selective separation of perrhenate from acidic wastewater by super-stable, superhydrophobic, and recyclable biosorbent

期刊论文

矿井低压电网选择性漏电保护系统总体设计与实现

孙玉坤,朱志莹,黄振跃,唐平

期刊论文

Extractive desulfurization of model fuels with a nitrogen-containing heterocyclic ionic liquid

期刊论文