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Effects of ancillary ligands in acceptorless benzyl alcohol dehydrogenation mediated by phosphine-free cobalt complexes

《化学科学与工程前沿（英文）》 2023年第17卷第3期页码 314-325 doi: 10.1007/s11705-022-2219-2

摘要： Acceptorless alcohol dehydrogenation stands out as one of the most promising strategies in hydrogen storage technologies. Among various catalytic systems for this reaction, cost-effective molecular catalysts using phosphine-free ligands have gained considerable attention. However, the central challenge for using non-precious metals is to overcome the propensity of reacting by one-electron pathway. Herein, we synthesized a phosphine-free η⁵-C₅Me₅-Co complex by using the metal–ligand cooperative strategy and compared its activity with analogous catalysts toward acceptorless alcohol dehydrogenation. The catalyst showed excellent performance with a turnover number of 130.4 and a selectivity close to 100%. The improved performance among the class of η⁵-C₅Me₅-Co complexes could be attributed to the more accessible Co center and its cooperation with the redox-active ligand. To further study the systematic structure-activity relationship, we investigated the electronic structures of η⁵-C₅Me₅-Co complexes by a set of characterizations. The results showed that the redox-active ligand has a significant influence on the η⁵-C₅Me₅-Co moiety. In the meantime, the proximal O⁻/OH group is beneficial for shuttling protons. For the catalytic cycle, two dehydrogenation scenarios were interrogated through density functional theory, and the result suggested that the outer-sphere pathway was preferred. The formation of a dihydrogen complex was the rate-determining step with a ΔG value of 16.9 kcal∙mol^‒1. The electron population demonstrated that the η⁵-C₅Me₅ ligand played a key role in stabilizing transition states during dehydrogenation steps. This work identified the roles of vital ligand components to boost catalytic performance and offered rationales for designing metal–ligand cooperative nonprecious metal complexes.

关键词： acceptorless alcohol dehydrogenation η⁵-C₅Me₅-Co metal–ligand cooperation theoretical calculation

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Surface modification by ligand growth strategy for dense copper bismuth film as photocathode to enhance

《能源前沿（英文）》 doi: 10.1007/s11708-023-0893-5

摘要： Hydrogen production from photoelectrochemical (PEC) water splitting has been regarded as a promising way to utilize renewable and endless solar energy. However, semiconductor film grown on photoelectrode suffers from numerous challenges, leading to the poor PEC performance. Herein, a straightforward sol-gel method with the ligand-induced growth strategy was employed to obtain dense and homogeneous copper bismuthate photocathodes for PEC hydrogen evolution reaction. By various characterizations, it was found that the nucleation and surface growth of CuBi₂O₄ layer induced by 2-methoxyethanol ligand (2-CuBi₂O₄) demonstrated a decent crystallinity and coverage, as well as a large grain size and a low oxygen vacancy concentration, leading to the good ability of light absorption and carrier migration. Consequently, under simulated sunlight irradiation (AM1.5G, 100 mW/cm²), the 2-CuBi₂O₄ photocathode achieved an enhanced photocurrent density of −1.34 mA·cm⁻² at 0.4 V versus the reversible hydrogen electrode and a promising applied bias photon-to-current efficiency of 0.586%. This surface modification by ligand growth strategy will shed light on the future design of advanced photoelectrodes for PEC water splitting.

关键词： copper bismuthate photocathode ligand growth strategy dense film PEC

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Highly selective detection of copper(II) by a “ligand-free” conjugated copolymer in nucleophilic solvents

Weixing Deng, Pengfei Sun, Quli Fan, Lei Zhang, Tsuyoshi Minami

《化学科学与工程前沿（英文）》 2020年第14卷第1期页码 105-111 doi: 10.1007/s11705-019-1791-6

摘要： The synthesis of -cyclohexyl carbamate-attached fluorene- -phenylene copolymer (PFPNCC) and the use of PFPNCC as a “ligand-free” fluorescent chemosensor for Cu(II) are described. Addition of Cu(II) can efficiently quench the fluorescence of PFPNCC in nucleophilic solvents such as DMF and DMSO, but not in low nucleophilic solvents such as 1,4-dioxane and THF. Ultraviolet-visible spectra of the mixture of the conjugated polymer and Cu(II) indicate the presence of a reduced Cu(I) ion in the solution. Furthermore, fluorescence recovery of PFPNCC observed at low temperature suggests that the quenching and reducing mechanism is most probably due to a photo-induced electron transfer from excited PFPNCC to Cu(II). Our findings provide a novel strategy for highly selective conjugated polymer-based chemosensors for various target analytes, albeit “ligand-free”.

关键词： ligand-free fluorescent chemosensor copper photo-induced electron transfer

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The cooperation effect of Ni and Pt in the hydrogenation of acetic acid

《化学科学与工程前沿（英文）》 2022年第16卷第3期页码 397-407 doi: 10.1007/s11705-021-2076-4

摘要： The catalytic hydrogenation of carboxylic acid to alcohols is one of the important strategies for the conversion of biomass. Herein, a series of Ni-doped PtSn catalysts were prepared, characterized and studied in the hydrogenation of acetic acid. The Ni dopant has a strong interaction with Pt, which promotes the hydrogen adsorption, providing an activated hydrogen-rich environment for the hydrogenation. Meanwhile, the presence of Ni also improves the Pt dispersion, giving more accessible active sites for hydrogen activation. The cooperation of Pt and Ni significantly promotes the catalytic activity of the hydrogenation of acetic acid to ethanol. As a result, the catalyst with 0.1% Ni exhibits the best reaction activity, and its space time yield is twice as that of the PtSn/SiO₂ catalyst. It provides a meaningful instruction on the catalyst design for the carboxylic acid hydrogenation.

关键词： acetic acid ethanol hydrogenation Pt Ni cooperation effect

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Synthesis of vinylferrocene and the ligand-exchange reaction between its copolymer and carbon nanotubes

Ran SHI,Hai WANG,Ping TANG,Yuezhen BIN

《化学科学与工程前沿（英文）》 2014年第8卷第2期页码 171-178 doi: 10.1007/s11705-014-1428-8

摘要： To improve the dispersibility of carbon nanotubes (CNTs), poly(vinylferrocene- -styrene) (poly(Vf- -St)), was grafted onto the surface of CNTs by a ligand-exchange reaction. Poly(Vf- -St) was obtained by a radical copolymerization reaction using styrene and vinylferrocene as the monomers. The vinylferrocene was synthesized from ferrocene via a Friedel-Crafts acylation. The molecular weight, molecular weight distribution, and amount of Vf in the poly(Vf- -St) were 1.32 × 10 , 1.69 and 17.6% respectively. The degree of grafting of the copolymer onto the CNTs surface was calculated from thermogravimetric analysis and varied from 27.1% to 79.7%. The addition of the poly(Vf- -St) greatly promoted the dispersibility of the modified CNTs in anhydrous alcohol. The electrical conductivity of composites prepared from the polymer-grafted CNTs and copolymer (acrylonitrile, 1,3-butadiene and styrene, ABS) strongly depended on the degree of grafting. These results show that the amount of polymer grafted onto the surface of CNTs can be controlled and that the electrical properties of composites prepared with these grafted polymers can be tuned.

关键词： vinylferrocene poly (Vf-co-St) CNTs dispersibility

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Effect of ligand chain length on hydrophobic charge induction chromatography revealed by molecular dynamics

Lin ZHANG, Yan SUN

《化学科学与工程前沿（英文）》 2013年第7卷第4期页码 456-463 doi: 10.1007/s11705-013-1357-y

摘要： Hydrophobic charge induction chromatography (HCIC) is a mixed-mode chromatography which is advantageous for high adsorption capacity and facile elution. The effect of the ligand chain length on protein behavior in HCIC was studied. A coarse-grain adsorbent pore model established in an earlier work was modified to construct adsorbents with different chain lengths, including one with shorter ligands (CL2) and one with longer ligands (CL4). The adsorption, desorption, and conformational transition of the proteins with CL2 and CL4 were examined using molecular dynamics simulations. The ligand chain length has a significant effect on both the probability and the irreversibility of the adsorption/desorption. Longer ligands reduced the energy barrier of adsorption, leading to stronger and more irreversible adsorption, as well as a little more unfolding of the protein. The simulation results elucidated the effect of the ligand chain length, which is beneficial for the rational design of adsorbents and parameter optimization for high-performance HCIC.

关键词： adsorption desorption irreversibility protein conformational transition molecular dynamics simulation

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The Research of Business Process Management-based on The Changqing Oil Field Cooperation Project

Ning Hui,Xiao-wei Zhou,Qing-qing Chang

《工程管理前沿（英文）》 2015年第2卷第2期页码 182-187 doi: 10.15302/J-FEM-2015027

摘要： This paper elaborates on defects in the PetrolChina Changqing?Oilfield Cooperation Management Project in an attempt to improve future cooperative efforts. The paper focuses on the drawbacks in the existing management process and analyzes the process by using current information management methods. This effort is made in hopes of arriving at the most efficient and effective method to redesign the existing processes.

关键词： cooperation project process optimization management improvement

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New Challenges, New Opportunities and New Measures for Oil and Gas Cooperation in the Belt and Road

Yu-pu Wang,He Liu

《工程管理前沿（英文）》 2016年第3卷第4期页码 301-313 doi: 10.15302/J-FEM-2016055

摘要： First-mover advantage and solid foundation of oil and gas cooperation is very important to the Belt and Road Initiative. Deeply studied opportunities and challenges of oil and gas cooperation have far-reaching significance to the cooperation in other industries in the Belt and Road. In this article, based on the systematic analysis of the oil and gas supply security, investment environment, regional win-win situation in oil and gas cooperation, new opportunities and challenges about upstream, pipeline, refining, trade, warehousing, engineering technology and equipment are studied. Enhancing capacities in four areas and implementing the 16 measures are given for deepening oil and gas cooperation in the future. Meanwhile, this article also gives suggestions and cooperation directions for countries and companies.

关键词： the Belt and Road oil & gas cooperation new challenges new opportunities new measures

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Fabrication of recyclable Fe chelated aminated polypropylene fiber for efficient clean-up of phosphate wastewater

《化学科学与工程前沿（英文）》 2023年第17卷第7期页码 840-852 doi: 10.1007/s11705-022-2253-0

摘要： Herein, a Fe³⁺-loaded aminated polypropylene fiber has been reported as an efficient phosphate adsorbent. The remarkable phosphate removal ability of the fiber is due to Fe³⁺ immobilization, and it demonstrates a maximum adsorption capacity of 33.94 mg·P·g^–1. Adsorption experiments showed that the fiber is applicable over a wide pH range from 2 to 9. Furthermore, the adsorption kinetics and isotherm data were consistent with the pseudo-second-order and Langmuir adsorption models, respectively. The adsorption equilibrium of the fiber for phosphate was reached within 60 min, indicating an efficient monolayer chemisorption process. Moreover, the adsorbent maintained prominent phosphate removal in the presence of competitive ions such as NO₃^– and Cl^–, exhibiting high selectivity. More importantly, the fiber demonstrated excellent reusability (5 times) and low adsorption limit below 0.02 mg·P·g^–1. In addition, the phosphate removal efficiency of the fiber can exceed 99% under continuous flow conditions. The adsorption mechanism was studied by X-ray photoelectron spectroscopy, showing that the adsorption of phosphate on the fiber mainly depended on the chemical adsorption of the modified Fe³⁺. Overall, this study proves that the fiber possesses many advantages for phosphate removal, including high adsorption efficiency, lower treatment limit, good recyclability, and environmental friendliness.

关键词： phosphate adsorption aminated polypropylene fiber Fe³⁺ ligand exchange reusability

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能源国际合作保障我国能源安全探讨

王珺,曹阳,王玉生,饶建业

《中国工程科学》 2021年第23卷第1期页码 118-123 doi: 10.15302/J-SSCAE-2021.01.019

摘要：

能源安全是关系国家经济社会发展的全局性、战略性问题，对国家繁荣发展、人民生活改善、社会长治久安至关重要。能源国际合作在保障我国能源安全方面始终发挥着重要作用，近年来随着能源安全的内涵向多维度转化，能源国际合作的定位和主要任务也面临更新和演变。本文基于国内外能源领域的最新形势，兼顾能源安全观的新内涵，对新时期我国能源国际合作的定位进行了全面阐述，着重探讨和分析近期能源国际合作中值得关注的重点方向。研究提出，新能源安全观对我国能源国际合作提出了新的更高要求，近期应重点推动建立多元化的油气进口和贸易格局，加强与周边国家的电力互联互通，深化先进能源技术方面的合作，积极参与并引领全球能源治理，为保障开放条件下的能源安全奠定坚实基础。

关键词：能源国际合作能源安全油气进口电力互联互通能源技术合作全球能源治理

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Robust cooperation of connected vehicle systems with eigenvalue-bounded interaction topologies in the

Keqiang LI, Feng GAO, Shengbo Eben LI, Yang ZHENG, Hongbo GAO

《机械工程前沿（英文）》 2018年第13卷第3期页码 354-367 doi: 10.1007/s11465-018-0486-x

摘要：

This study presents a distributed H-infinity control method for uncertain platoons with dimensionally and structurally unknown interaction topologies provided that the associated topological eigenvalues are bounded by a predesigned range. With an inverse model to compensate for nonlinear powertrain dynamics, vehicles in a platoon are modeled by third-order uncertain systems with bounded disturbances. On the basis of the eigenvalue decomposition of topological matrices, we convert the platoon system to a norm-bounded uncertain part and a diagonally structured certain part by applying linear transformation. We then use a common Lyapunov method to design a distributed H-infinity controller. Numerically, two linear matrix inequalities corresponding to the minimum and maximum eigenvalues should be solved. The resulting controller can tolerate interaction topologies with eigenvalues located in a certain range. The proposed method can also ensure robustness performance and disturbance attenuation ability for the closed-loop platoon system. Hardware-in-the-loop tests are performed to validate the effectiveness of our method.

关键词： automated vehicles platoon distributed control robustness

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Limit span of self-anchored cable-stayed suspension cooperation system bridge based on strength

Zhe ZHANG , Huili WANG , Xiaomeng GE , Sifeng QIN ,

《结构与土木工程前沿（英文）》 2009年第3卷第3期页码 286-291 doi: 10.1007/s11709-009-0045-y

摘要： The limit span of self-anchored cable-stayed suspension bridge is deduced. The relations among the geometrical parameters, loads and material characteristics are also analyzed. Based on the material strength and commonly used materials, the limit spans of self-anchored cable-stayed suspension bridges with concrete girder or steel girder under vertical static load are discussed in detail. The corresponding upper limit spans and the effect of the factors on the span are given. The results indicate that increasing rise-span ratio, height-span ratio and cable-stayed segment length or reducing the second dead load could increase the cooperation system span.

关键词： cable-stayed suspension self-anchored limit span

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A ternary mechanism for the facilitated transfer of metal ions onto metal–organic frameworks: implications

《化学科学与工程前沿（英文）》页码 1632-1642 doi: 10.1007/s11705-022-2187-6

摘要： Although metal–organic frameworks offer a new platform for developing versatile sorption materials, yet coordinating the functionality, structure and component of these materials remains a great challenge. It depends on a comprehensive knowledge of a “real sorption mechanism”. Herein, a ternary mechanism for U(VI) uptake in metal–organic frameworks was reported. Analogous MIL-100s (Al, Fe, Cr) were prepared and studied for their ability to sequestrate U(VI) from aqueous solutions. As a result, MIL-100(Al) performed the best among the tested materials, and MIL-100(Cr) performed the worst. The nuclear magnetic resonance technique combined with energy-dispersive X-ray spectroscopy and zeta potential measurement reveal that U(VI) uptake in the three metal–organic frameworks involves different mechanisms. Specifically, hydrated uranyl ions form outer-sphere complexes in the surface of MIL-100s (Al, Fe) by exchanging with hydrogen ions of terminal hydroxyl groups (Al-OH₂, Fe-OH₂), and/or, hydrated uranyl ions are bound directly to Al(III) center in MIL-100(Al) through a strong inner-sphere coordination. For MIL-100(Cr), however, the U(VI) uptake is attributed to electrostatic attraction. Besides, the sorption mechanism is also pH and ionic strength dependent. The present study suggests that changing metal center of metal–organic frameworks and sorption conditions alters sorption mechanism, which helps to construct effective metal–organic frameworks-based sorbents for water purification.

关键词： U(VI) metal–organic frameworks adsorption mechanism metal node

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中国汽车工业的发展道路：回顾与展望——合作与自主问题

郭孔辉

《中国工程科学》 2004年第6卷第8期页码 17-20

摘要：

文章对中国汽车工业发展道路存在的重大分歧和争论——“合作与自主问题”进行了分析和阐述，提出了中国汽车工业发展的出路，并阐明通过主动争取双赢平等的国内外合作，创造自有知识的自主品牌，形成自己的核心技术；中国完全有能力也有条件走自主开发之路。

关键词：中国汽车工业发展道路合作与自主

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世界油气上游国际合作的形势和机会

童晓光

《中国工程科学》 2011年第13卷第4期页码 15-19

摘要：

指出中国利用国外油气的必要性，重点分析了伊拉克、伊朗、巴西、加拿大、委内瑞拉和北美油气上游合作的机会及世界油气国际合作的合同变化趋势，提出了当前扩大油气上游国际合作的主要方向。

关键词：油气上游国际合作伊拉克深水油气勘探重油和油砂非常规天然气

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标题作者时间类型操作

Effects of ancillary ligands in acceptorless benzyl alcohol dehydrogenation mediated by phosphine-free cobalt complexes

期刊论文

Surface modification by ligand growth strategy for dense copper bismuth film as photocathode to enhance

期刊论文

Highly selective detection of copper(II) by a “ligand-free” conjugated copolymer in nucleophilic solvents

Weixing Deng, Pengfei Sun, Quli Fan, Lei Zhang, Tsuyoshi Minami

期刊论文

The cooperation effect of Ni and Pt in the hydrogenation of acetic acid

期刊论文

Synthesis of vinylferrocene and the ligand-exchange reaction between its copolymer and carbon nanotubes

Ran SHI,Hai WANG,Ping TANG,Yuezhen BIN

期刊论文

Effect of ligand chain length on hydrophobic charge induction chromatography revealed by molecular dynamics

Lin ZHANG, Yan SUN

期刊论文

The Research of Business Process Management-based on The Changqing Oil Field Cooperation Project

Ning Hui,Xiao-wei Zhou,Qing-qing Chang

期刊论文

New Challenges, New Opportunities and New Measures for Oil and Gas Cooperation in the Belt and Road

Yu-pu Wang,He Liu

期刊论文

Fabrication of recyclable Fe chelated aminated polypropylene fiber for efficient clean-up of phosphate wastewater

期刊论文

能源国际合作保障我国能源安全探讨

王珺,曹阳,王玉生,饶建业

期刊论文

Robust cooperation of connected vehicle systems with eigenvalue-bounded interaction topologies in the

Keqiang LI, Feng GAO, Shengbo Eben LI, Yang ZHENG, Hongbo GAO

期刊论文

Limit span of self-anchored cable-stayed suspension cooperation system bridge based on strength

Zhe ZHANG , Huili WANG , Xiaomeng GE , Sifeng QIN ,

期刊论文

A ternary mechanism for the facilitated transfer of metal ions onto metal–organic frameworks: implications

期刊论文

中国汽车工业的发展道路：回顾与展望——合作与自主问题

郭孔辉

期刊论文

世界油气上游国际合作的形势和机会

童晓光

期刊论文

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