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期刊论文 273

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DX桩 2

催化剂 2

力学性能 2

单边直线感应电机 2

沉降 2

Au/Ti双功能催化剂 1

CO2 加氢 1

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Pt–Ba–Ce/γ-Al2O3 催化剂,物理化学性质,NOx存储和还原,NOx 排放,H2 还原剂 1

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Promising approach for preparing metallic single-atom catalysts: electrochemical deposition

《能源前沿(英文)》 2022年 第16卷 第4期   页码 537-541 doi: 10.1007/s11708-022-0837-5

Oxygen reduction electrocatalysis: From conventional to single-atomic platinum-based catalysts for proton

《能源前沿(英文)》 doi: 10.1007/s11708-023-0907-3

摘要: Platinum (Pt)-based materials are still the most efficient and practical catalysts to drive the sluggish kinetics of cathodic oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). However, their catalysis and stability performance still need to be further improved in terms of corrosion of both carbon support and Pt catalyst particles as well as Pt loading reduction. Based on the developed synthetic strategies of alloying/nanostructuring Pt particles and modifying/innovating supports in developing conventional Pt-based catalysts, Pt single-atom catalysts (Pt SACs) as the recently burgeoning hot materials with a potential to achieve the maximum utilization of Pt are comprehensively reviewed in this paper. The design thoughts and synthesis of various isolated, alloyed, and nanoparticle-contained Pt SACs are summarized. The single-atomic Pt coordinating with non-metals and alloying with metals as well as the metal-support interactions of Pt single-atoms with carbon/non-carbon supports are emphasized in terms of the ORR activity and stability of the catalysts. To advance further research and development of Pt SACs for viable implementation in PEMFCs, various technical challenges and several potential research directions are outlined.

关键词: oxygen reduction electrocatalysis     Pt single-atom catalysts     conventional Pt-based catalysts     design thoughts and synthesis     metal-support interactions    

Spin polarization strategy to deploy proton resource over atomic-level metal sites for highly selective CO electrolysis

《化学科学与工程前沿(英文)》 2022年 第16卷 第12期   页码 1772-1781 doi: 10.1007/s11705-022-2197-4

摘要: Unlocking of the extremely inert C=O bond during electrochemical CO2 reduction demands subtle regulation on a key “resource”, protons, necessary for intermediate conversion but also readily trapped in water splitting, which is still challenging for developing efficient single-atom catalysts limited by their structural simplicity usually incompetent to handle this task. Incorporation of extra functional units should be viable. Herein, a proton deployment strategy is demonstrated via “atomic and nanostructured iron (A/N-Fe) pairs”, comprising atomically dispersed iron active centers spin-polarized by nanostructured iron carbide ferromagnets, to boost the critical protonation steps. The as-designed catalyst displays a broad window (300 mV) for CO selectivity > 90% (98% maximum), even outperforming numerous cutting-edge M–N–C systems. The well-placed control of proton dynamics by A/N-Fe can promote *COOH/*CO formation and simultaneously suppress H2 evolution, benefiting from the magnetic-proximity-induced exchange splitting (spin polarization) that properly adjusts energy levels of the Fe sites’ d-shells, and further those of the adsorbed intermediates’ antibonding molecular orbitals.

关键词: CO2 electrolysis     single-atom catalysts     spin polarization     proton dynamics     in situ IR spectroscopy     kinetic isotope effect    

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    

Real atom economy and its application for evaluation the green degree of a process

Weihan WANG, Jing Lü, Li ZHANG, Zhenhua LI

《化学科学与工程前沿(英文)》 2011年 第5卷 第3期   页码 349-354 doi: 10.1007/s11705-010-1030-7

摘要: Green chemistry has attracted more attention in the past century. Among the 12 principles of green chemistry, only atom economy and E factor can be expressed quantitatively to depict the impact of a chemical process to environment. Atom economy was thought better than the traditional yield for evaluating the atom efficiency of raw materials. But it is not enough to reflect the conversion degree of raw material. In this paper, we proposed the concept of real atom economy (RAE) as a metric. RAE could combine the above two factors together to better express the green degree of a process. We further suggested an equation to correlate E factor with RAE. The concept of RAE is proved to be helpful for estimating an environmentally benign process.

关键词: green chemistry     real atom economy     E factor     atom economy     yield    

Electrochemical CO reduction to C products over CuZn intermetallic catalysts synthesized by electrodeposition

《能源前沿(英文)》 doi: 10.1007/s11708-023-0898-0

摘要: Electrocatalytic CO2 reduction (ECR) offers an attractive approach to realizing carbon neutrality and producing valuable chemicals and fuels using CO2 as the feedstock. However, the lack of cost-effective electrocatalysts with better performances has seriously hindered its application. Herein, a one-step co-electrodeposition method was used to introduce Zn, a metal with weak *CO binding energy, into Cu to form Cu/Zn intermetallic catalysts (Cu/Zn IMCs). It was shown that, using an H-cell, the high Faradaic efficiency of C2+ hydrocarbons/alcohols (FEC2+) could be achieved in ECR by adjusting the surface metal components and the applied potential. In suitable conditions, FEC2+ and current density could be as high as 75% and 40 mA/cm2, respectively. Compared with the Cu catalyst, the Cu/Zn IMCs have a lower interfacial charge transfer resistance and a larger electrochemically active surface area (ECSA), which accelerate the reaction. Moreover, the *CO formed on Zn sites can move to Cu sites due to its weak binding with *CO, and thus enhance the C–C coupling on the Cu surface to form C2+ products.

关键词: carbon dioxide electroreduction     electrochemistry     co-electrodeposition     intermetallic catalysts     value-added chemicals    

Current challenge and perspective of PGM-free cathode catalysts for PEM fuel cells

Gang WU

《能源前沿(英文)》 2017年 第11卷 第3期   页码 286-298 doi: 10.1007/s11708-017-0477-3

摘要: To significantly reduce the cost of proton exchange membrane fuel cells, platinum-group metal (PGM)-free cathode catalysts are highly desirable. Current M-N-C (M: Fe, Co or Mn) catalysts are considered the most promising due to their encouraging performance. The challenge thus has been their stability under acidic conditions, which has hindered their use for any practical applications. In this review, based on the author’s research experience in the field for more than 10 years, current challenges and possible solutions to overcome these problems were discussed. The current Edisonian approach (i.e., trial and error) to developing PGM-free catalysts has been ineffective in achieving revolutionary breakthroughs. Novel synthesis techniques based on a more methodological approach will enable atomic control and allow us to achieve optimal electronic and geometric structures for active sites uniformly dispersed within the 3D architectures. Structural and chemical controlled precursors such as metal-organic frameworks are highly desirable for making catalysts with an increased density of active sites and strengthening local bonding structures among N, C and metals. Advanced electrochemical and physical characterization, such as electron microscopy and X-ray absorption spectroscopy should be combined with first principle density functional theory (DFT) calculations to fully elucidate the active site structures.

关键词: oxygen reduction     fuel cells     cathode     nonprecious metal catalysts     carbon nanocomposites    

Selective preparation for biofuels and high value chemicals based on biochar catalysts

《能源前沿(英文)》 2023年 第17卷 第5期   页码 635-653 doi: 10.1007/s11708-023-0878-4

摘要: The reuse of biomass wastes is crucial toward today’s energy and environmental crisis, among which, biomass-based biochar as catalysts for biofuel and high value chemical production is one of the most clean and economical solutions. In this paper, the recent advances in biofuels and high chemicals for selective production based on biochar catalysts from different biomass wastes are critically summarized. The topics mainly include the modification of biochar catalysts, the preparation of energy products, and the mechanisms of other high-value products. Suitable biochar catalysts can enhance the yield of biofuels and higher-value chemicals. Especially, the feedstock and reaction conditions of biochar catalyst, which affect the efficiency of energy products, have been the focus of recent attentions. Mechanism studies based on biochar catalysts will be helpful to the controlled products. Therefore, the design and advancement of the biochar catalyst based on mechanism research will be beneficial to increase biofuels and the conversion efficiency of chemicals into biomass. The advanced design of biochar catalysts and optimization of operational conditions based on the biomass properties are vital for the selective production of high-value chemicals and biofuels. This paper identifies the latest preparation for energy products and other high-value chemicals based on biochar catalysts progresses and offers insights into improving the yield of high selectivity for products as well as the high recyclability and low toxicity to the environment in future applications.

关键词: biomass     biochar catalysts     biofuels     high chemicals    

Catalytic combustion of volatile organic compounds using perovskite oxides catalysts—a review

《化学科学与工程前沿(英文)》 2023年 第17卷 第11期   页码 1649-1676 doi: 10.1007/s11705-023-2324-x

摘要: With the rapid development of industry, volatile organic compounds (VOCs) are gaining attention as a class of pollutants that need to be eliminated due to their adverse effects on the environment and human health. Catalytic combustion is the most popular technology used for the removal of VOCs as it can be adapted to different organic emissions under mild conditions. This review first introduces the hazards of VOCs, their treatment technologies, and summarizes the treatment mechanism issues. Next, the characteristics and catalytic performance of perovskite oxides as catalysts for VOC removal are expounded, with a special focus on lattice distortions and surface defects caused by metal doping and surface modifications, and on the treatment of different VOCs. The challenges and the prospects regarding the design of perovskite oxides catalysts for the catalytic combustion of VOCs are also discussed. This review provides a reference base for improving the performance of perovskite catalysts to treat VOCs.

关键词: perovskite oxides     volatile organic compounds     catalytic combustion     reaction mechanism    

Enhanced activity of bimetallic Fe-Cu catalysts supported on ceria toward water gas shift reaction: synergistic

《化学科学与工程前沿(英文)》 2023年 第17卷 第12期   页码 1962-1972 doi: 10.1007/s11705-023-2359-z

摘要: Within the “hydrogen chain”, the high-temperature water gas shift reaction represents a key step to improve the H2 yield and adjust the H2/COx ratio to fit the constraints of downstream processes. Despite the commercial application of the high-temperature water gas shift, novel catalysts characterized by higher intrinsic activity (especially at low temperatures), good thermal stability, and no chromium content are needed. In this work, we propose bimetallic iron-copper catalysts supported on ceria, characterized by low active phase content (iron oxide + copper oxide < 5 wt %). Fresh and used samples were characterized by inductively coupled plasma mass spectrometry, X-ray diffraction, nitrogen physisorption, scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, and temperature programmed reduction in hydrogen to relate physicochemical features and catalytic activity. The sample with iron/copper ≈ 1 and 4 wt % active phase content showed the best catalytic properties in terms of turnover frequency, no methane formation, and stability. Its unique properties were due to both strong iron-copper interaction and strong metal-support interaction, leading to outstanding redox behavior.

关键词: water gas shift     iron     copper     bimetallic catalysts     ceria     hydrogen    

Crystallographic orientation effect on cutting-based single atomic layer removal

Wenkun XIE, Fengzhou FANG

《机械工程前沿(英文)》 2020年 第15卷 第4期   页码 631-644 doi: 10.1007/s11465-020-0599-x

摘要: The ever-increasing requirements for the scalable manufacturing of atomic-scale devices emphasize the significance of developing atomic-scale manufacturing technology. The mechanism of a single atomic layer removal in cutting is the key basic theoretical foundation for atomic-scale mechanical cutting. Material anisotropy is among the key decisive factors that could not be neglected in cutting at such a scale. In the present study, the crystallographic orientation effect on the cutting-based single atomic layer removal of monocrystalline copper is investigated by molecular dynamics simulation. When undeformed chip thickness is in the atomic scale, two kinds of single atomic layer removal mechanisms exist in cutting-based single atomic layer removal, namely, dislocation motion and extrusion, due to the differing atomic structures on different crystallographic planes. On close-packed crystallographic plane, the material removal is dominated by the shear stress-driven dislocation motion, whereas on non-close packed crystallographic planes, extrusion-dominated material removal dominates. To obtain an atomic, defect-free processed surface, the cutting needs to be conducted on the close-packed crystallographic planes of monocrystalline copper.

关键词: ACSM     single atomic layer removal mechanism     crystallographic orientation effect     mechanical cutting     Manufacturing III    

Design and analysis of partially decoupled translational parallel mechanisms with single-loop structures

《机械工程前沿(英文)》 2022年 第17卷 第3期 doi: 10.1007/s11465-022-0695-1

摘要: This study presents a family of novel translational parallel mechanisms (TPMs) with single-loop topological structures. The proposed mechanism consists of only revolute and prismatic joints. The novel TPMs are simpler in structure and have fewer joints and components than the well-known Delta Robot. Four types of 2-degree of freedom driving systems are applied to different limb structures to avoid the moving actuator that causes the problem of increased moving mass. Four sample TPMs are constructed using the synthesized limbs, and one of them is investigated in terms of kinematic performance. First, a position analysis is performed and validated through numerical simulation to reveal the characteristics of partially decoupled motion, which improves the controllability of TPM. Second, singular configurations are identified, and the resulting singularity curve is obtained. Lastly, the workspace of TPM is analyzed, and the relationship between the singular configurations and the reachable workspace is explored. The workspace of the 3-CRR (C denotes the cylindrical joint and R denotes the revolute joint) translational mechanism is also presented to prove that the proposed TPM has a fairly large workspace.

关键词: translational parallel mechanism     single loop     multiple driving system     workspace analysis     singularity    

NiBO (B = Mn or Co) catalysts for NH-SCR of NO at low-temperature in microwave field

《环境科学与工程前沿(英文)》 2023年 第17卷 第8期 doi: 10.1007/s11783-023-1696-y

摘要:

● Microwave-assisted catalytic NH3-SCR reaction over spinel oxides is carried out.

关键词: Microwave field     Spinel oxides     NOx     Selective catalytic reduction    

Moving policy and regulation forward for single-use plastic alternatives

《环境科学与工程前沿(英文)》 2021年 第15卷 第3期 doi: 10.1007/s11783-021-1423-5

摘要: Single-use plastics are often used once or cannot be reused for extended periods. They are widely consumed with the rapid development of social economy. The waste generated by single-use plastics threatens ecosystem health by entering the environment and ultimately restricts sustainable human development. The innovation of sustainable and environmentally friendly single-use plastic alternative materials and the joint participation of governments, enterprises and the public are promising technologies and management approaches that can solve the problem of single-use plastics wastes. The development of single-use plastic alternative products can be promoted fundamentally only by improving relevant legislation and standards, providing differentiated industrial policies, encouraging scientific and technological innovation and expanding public participation.

关键词: Single-use plastic alternatives     Policy     Regulation     Sustainable development    

钱学森与材料设计

于翘

《中国工程科学》 2002年 第4卷 第5期   页码 1-6

摘要:

扼要地介绍了近20年来著名科学家钱学森积极倡导和有力推动的关于“材料设计”的思想、理论、层次、方法和体系。经历届“八六三”计划专家组的努力,“材料设计”己列入国家级新材料发展计划,并取得了可喜的成果。

关键词: 钱学森     材料设计     原子与分子工程     材料科学与材料技术体系    

标题 作者 时间 类型 操作

Promising approach for preparing metallic single-atom catalysts: electrochemical deposition

期刊论文

Oxygen reduction electrocatalysis: From conventional to single-atomic platinum-based catalysts for proton

期刊论文

Spin polarization strategy to deploy proton resource over atomic-level metal sites for highly selective CO electrolysis

期刊论文

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

期刊论文

Real atom economy and its application for evaluation the green degree of a process

Weihan WANG, Jing Lü, Li ZHANG, Zhenhua LI

期刊论文

Electrochemical CO reduction to C products over CuZn intermetallic catalysts synthesized by electrodeposition

期刊论文

Current challenge and perspective of PGM-free cathode catalysts for PEM fuel cells

Gang WU

期刊论文

Selective preparation for biofuels and high value chemicals based on biochar catalysts

期刊论文

Catalytic combustion of volatile organic compounds using perovskite oxides catalysts—a review

期刊论文

Enhanced activity of bimetallic Fe-Cu catalysts supported on ceria toward water gas shift reaction: synergistic

期刊论文

Crystallographic orientation effect on cutting-based single atomic layer removal

Wenkun XIE, Fengzhou FANG

期刊论文

Design and analysis of partially decoupled translational parallel mechanisms with single-loop structures

期刊论文

NiBO (B = Mn or Co) catalysts for NH-SCR of NO at low-temperature in microwave field

期刊论文

Moving policy and regulation forward for single-use plastic alternatives

期刊论文

钱学森与材料设计

于翘

期刊论文