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Shape selective catalysis in methylation of toluene: Development, challenges and perspectives

Jian Zhou, Zhicheng Liu, Yangdong Wang, Dejin Kong, Zaiku Xie

《化学科学与工程前沿（英文）》 2018年第12卷第1期页码 103-112 doi: 10.1007/s11705-017-1671-x

摘要： Toluene methylation with methanol offers an alternative method to produce -xylene by gathering methyl group directly from C1 chemical sources. It supplies a “molecular engineering” process to realize directional conversion of toluene/methanol molecules by selective catalysis in complicated methylation system. In this review, we introduce the synthesis method of -xylene, the development history of methylation catalysts and reaction mechanism, and the effect of reaction condition in -selective technical process. If constructing -xylene as the single target product, the major challenge to develop -selective toluene methylation is to improve the -xylene selectivity without, or as little as possible, losing the fraction of methanol for methylation. To reach higher yield of -xylene and more methanol usage in methylation, zeolite catalyst design should consider improving mass transfer and afterwards covering external acid sites by surface modification to get short “micro-tunnels” with shape selectivity. A solid understanding of mass transfer will benefit realizing the aim of converting more methanol feedstock into -methyl group.

关键词： shape selective catalysis methylation of toluene

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Morphology selective construction of

Maher Darwish, Ali Mohammadi, Navid Assi, Samer Abuzerr, Youssef Alahmad

《化学科学与工程前沿（英文）》 2020年第14卷第4期页码 561-578 doi: 10.1007/s11705-019-1808-1

摘要： Controlled growth of Bi WO nanorods with exposed [0 0 1] facets and the fabrication of an Fe O -Bi WO magnetic composite by a microwave-assisted polyol process, were achieved in this study. The adsorptivity and photocatalytic performance of the composite toward sunset yellow dye degradation were greatly enhanced by the -cyclodextrin cavities on its surface, firmly anchored through a cetyltrimethylammonium bromide linkage. A series of examinations and characterizations were carried out to determine the influence of various factors on the morphological modulation-photocatalytic behavior of the pure Bi WO prior to final functionalization. Changing the pH of the precursor solution impacted the formation of 0D, 2D, and 3D structures; however, the presence of hexamethylenetetramine surfactant induced the development of 1D nanorod structure. A reasonable crystal growth mechanism was proposed to elucidate the formation process. Conversely, the mechanism of the activity enhancement of -cyclodextrin functionalized Fe O -Bi WO , compared to that of the non-functionalized samples, could be realized with the assistance of chemical trapping experiments on sunset yellow, and was confirmed on the colorless antibiotic (sulfamethoxazole). The high performance and durability of this composite can be attributed to the facet-dependent activity, large adsorption capacity due to inclusion interactions, enhanced visible light absorption, and efficient charge separation.

关键词： β-cyclodextrin Bi₂WO₆ shape controlled nanorod sunset yellow

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The abatement of major pollutants in air and water by environmental catalysis

Junhua LI, Hong HE, Chun HU, Jincai ZHAO

《环境科学与工程前沿（英文）》 2013年第7卷第3期页码 302-325 doi: 10.1007/s11783-013-0511-6

摘要： This review reports the research progress in the abatement of major pollutants in air and water by environmental catalysis. For air pollution control, the selective catalytic reduction of NO (SCR) by ammonia and hydrocarbons on metal oxide and zeolite catalysts are reviewed and discussed, as is the removal of Hg from flue gas by catalysis. The oxidation of Volatile organic compounds (VOCs) by photo- and thermal- catalysis for indoor air quality improvement is reviewed. For wastewater treatment, the catalytic elimination of inorganic and organic pollutants in wastewater is presented. In addition, the mechanism for the procedure of abatement of air and water pollutants by catalysis is discussed in this review. Finally, a research orientation on environment catalysis for the treatment of air pollutants and wastewater is proposed.

关键词： air pollution control wastewater treatment DeNO_x selective catalytic reduction (SCR) Volatile organic compounds (VOCs) environmental catalysis

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Recent advances in cycloaddition of CO with epoxides: halogen-free catalysis and mechanistic insights

《化学科学与工程前沿（英文）》 2023年第17卷第12期页码 1879-1894 doi: 10.1007/s11705-023-2354-4

摘要： The atom-economical cycloaddition of CO₂ with epoxides to synthesize cyclic carbonates is a promising route for valuable utilization of CO₂. Halogenide such as alkali metal halides and quaternary ammonium salt have been developed as the efficient catalysts. However, the spilled halogen causes equipment corrosion and affects the product purity. To address these concerns, the halogen-free cycloaddition of CO₂ with epoxides has always been desired. In this review, we systematically discussed the halogen-free catalysis for cycloaddition of CO₂ with epoxides from the mechanistic insights, aiming to promote the development of efficient halogen-free catalysts. Two types of catalysts, i.e., alternatives of halogen nucleophiles for epoxide activation, and bifunctional catalysts with Lewis acid-base sites for synergistic activation of CO₂ and epoxides are summarized and emphasized. Specially, metal oxides as the potential halogen-free catalysts are highlighted due to their flexible acid-base sites for synergistic activation of CO₂ and epoxides, facile preparation, and low cost.

关键词： carbon dioxide halogen-free catalysis cyclic carbonate mechanistic insight

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An extended thermo-mechanically coupled algorithm for simulation of superelasticity and shape memoryeffect in shape memory alloys

S. HASHEMI,H. AHMADIAN,S. MOHAMMADI

《结构与土木工程前沿（英文）》 2015年第9卷第4期页码 466-477 doi: 10.1007/s11709-015-0300-3

摘要： Thermo-mechanical coupling in shape memory alloys is a very complicated phenomenon. The heat generation/absorption during forward/reverse transformation can lead to temperature-dependent variation of its mechanical behavior in the forms of superelasticity and shape memory effect. However, unlike the usual assumption, slow loading rate cannot guarantee an isothermal process. A two-dimensional thermo-mechanically coupled algorithm is proposed based on the original model of Lagoudas to efficiently model both superelasticity and shape memory effects and the influence of various strain rates, aspect ratios and boundary conditions. To implement the coupled model into a finite element code, a numerical staggered algorithm is employed. A number of simulations are performed to verify the proposed approach with available experimental and numerical data and to assess its efficiency in solving complex SMA problems.

关键词： shape memory alloy thermo-mechanical coupling superplasticity shape memory effect

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Application of heterogeneous catalysis to biodiesel synthesis using microalgae oil

《环境科学与工程前沿（英文）》 2021年第15卷第5期 doi: 10.1007/s11783-020-1343-9

摘要：

• Microalgae oil application for biodiesel synthesis is discussed.

关键词： Biodiesel Heterogeneous catalysis Transesterification Microalgae oil

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Plasma-catalysis: Is it just a question of scale?

J. Christopher Whitehead

《化学科学与工程前沿（英文）》 2019年第13卷第2期页码 264-273 doi: 10.1007/s11705-019-1794-3

摘要： The issues of describing and understanding the changes in performance that result when a catalyst is placed into plasma are discussed. The different chemical and physical interactions that result and how their combination might produce beneficial results for the plasma-catalytic processing of different gas streams are outlined with particular emphasis being placed on the different range of spatial and temporal scales that must be considered both in experiment and modelling. The focus is on non-thermal plasma where the lack of thermal equilibrium creates a range of temperature scales that must be considered. This contributes in part to a wide range of inhomogeneity in different properties such as species concentrations and electric fields that must be determined experimentally by methods and be incorporated into modelling. It is concluded that plasma-catalysis is best regarded as conventional catalysis perturbed by the presence of a discharge, which modifies its operating conditions, properties and outcomes often in a very localised way. The sometimes used description “plasma-activated catalysis” is an apt one.

关键词： plasma catalysis plasma-activated catalysis non-thermal plasma CO₂ conversion

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Frontiers of Catalysis Chemistry and Technology

《化学科学与工程前沿（英文）》 2018年第12卷第1期页码 1-2 doi: 10.1007/s11705-018-1704-0

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Scaling up of cluster beam deposition technology for catalysis application

《化学科学与工程前沿（英文）》 2021年第15卷第6期页码 1360-1379 doi: 10.1007/s11705-021-2101-7

摘要： Many research works have demonstrated that the combination of atomically precise cluster deposition and theoretical calculations is able to address fundamental aspects of size-effects, cluster-support interactions, and reaction mechanisms of cluster materials. Although the wet chemistry method has been widely used to synthesize nanoparticles, the gas-phase synthesis and size-selected strategy was the only method to prepare supported metal clusters with precise numbers of atoms for a long time. However, the low throughput of the physical synthesis method has severely constrained its wider adoption for catalysis applications. In this review, we introduce the latest progress on three types of cluster source which have the most promising potential for scale-up, including sputtering gas aggregation source, pulsed microplasma cluster source, and matrix assembly cluster source. While the sputtering gas aggregation source is leading ahead with a production rate of ~20 mg·h^–1, the pulsed microplasma source has the smallest physical dimensions which makes it possible to compact multiple such devices into a small volume for multiplied production rate. The matrix assembly source has the shortest development history, but already show an impressive deposition rate of ~10 mg·h^–1. At the end of the review, the possible routes for further throughput scale-up are envisaged.

关键词： nanoparticle cluster cluster beam deposition magnetron sputtering heterogeneous catalysis

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Preface to special issue on “Advanced Materials and Catalysis”

《化学科学与工程前沿（英文）》 2021年第15卷第6期页码 1357-1359 doi: 10.1007/s11705-021-2119-x

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A novel shape memory alloy actuated soft gripper imitated hand behavior

《机械工程前沿（英文）》 2022年第17卷第4期 doi: 10.1007/s11465-022-0700-8

摘要： The limited length shrinkage of shape memory alloy (SMA) wire seriously limits the motion range of SMA-based gripper. In this paper, a new soft finger without silicone gel was designed based on pre bent SMA wire, and the finger was back to its original shape by heating SMA wire, rather than relying only on heat exchange with the environment. Through imitating palm movement, a structure with adjustable spacing between fingers was made using SMA spring and rigid spring. The hook structure design at the fingertip can form self-locking to further improve the load capacity of gripper. Through the long thin rod model, the relationship of the initial pre bent angle on the bending angle and output force of the finger was analyzed. The stress-strain model of SMA spring was established for the selection of rigid spring. Three grasping modes were proposed to adapt to the weight of the objects. Through the test of the gripper, it was proved that the gripper had large bending amplitude, bending force, and response rate. The design provides a new idea for the lightweight design and convenient design of soft gripper based on SMA.

关键词： shape memory alloy (SMA) pre bent wire gripper grasping mode lightweight

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Size and shape effects of MnFeO nanoparticles as catalysts for reductive degradation of dye pollutants

《环境科学与工程前沿（英文）》 2021年第15卷第5期页码 108-171 doi: 10.1007/s11783-021-1396-4

摘要： The magnetic nanoparticles that are easy to recycle have tremendous potential as a suitable catalyst for environmental toxic dye pollutant degradation. Rationally engineering shapes and tailoring the size of nanocatalysts are regarded as an effective manner for enhancing performances. Herein, we successfully synthesized three kinds of MnFe₂O₄ NPs with distinctive sizes and shapes as catalysts for reductive degradation of methylene blue, rhodamine 6G, rhodamine B, and methylene orange. It was found that the catalytic activities were dependent on the size and shape of the MnFe₂O₄ NPs and highly related to the surface-to-volume ratio and atom arrangements. Besides, all these nanocatalysts exhibit selectivity to different organic dyes, which is beneficial for their practical application in dye pollutant treatment. Furthermore, the MnFe₂O₄ NPs could be readily recovered by a magnet and reused more than ten times without appreciable loss of activity. The size and shape effects of MnFe₂O₄ nanoparticles demonstrated in this work not only accelerate further understanding the nature of nanocatalysts but also contribute to the precise design of nanoparticles catalyst for pollutant degradation.

关键词： Dye degradation MnFe₂O₄ nanoparticles Size and shape-control

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Preface to special issue on “Engineering Nanostructured Materials for Advanced Energy and Environmental Catalysis

《化学科学与工程前沿（英文）》 2023年第17卷第11期页码 1621-1622 doi: 10.1007/s11705-023-2365-1

摘要： Preface to special issue on “Engineering Nanostructured Materials for Advanced Energy and Environmental Catalysis”

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Temperature effects of shape memory alloys (SMAs) in damage control design of steel portal frames

Xiaoqun LUO, Hanbin GE, Tsutomu USAMI

《结构与土木工程前沿（英文）》 2012年第6卷第4期页码 348-357 doi: 10.1007/s11709-012-0176-4

摘要： The objective of the present study is to analytically investigate temperature effects of an axial-type seismic damper made of shape memory alloys (SMAs) equipped in steel frames. Based on a modified multilinear one dimensional constitutive model of SMAs, two types of SMAs are employed, which have different stress plateau and different stress growth rate with temperature increase. Temperature effects of SMA dampers on seismic performance upgrading are discussed in three aspects: different environment temperatures; rapid loading rate induced heat generation and different SMA fractions. The analysis indicates that the effect of environment temperature should be considered for the SMA damper in steel frames. However, the rapid loading rate induced heat generation has little adverse effect.

关键词： damage control design shape memory alloy temperature effect

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Recent advances in selective acetylene hydrogenation using palladium containing catalysts

Alan J. McCue, James A. Anderson

《化学科学与工程前沿（英文）》 2015年第9卷第2期页码 142-153 doi: 10.1007/s11705-015-1516-4

摘要： Recent advances with Pd containing catalysts for the selective hydrogenation of acetylene are described. The overview classifies enhancement of catalytic properties for monometallic and bimetallic Pd catalysts. Activity/selectivity of Pd catalysts can be modified by controlling particle shape/morphology or immobilisation on a support which interacts strongly with Pd particles. In both cases enhanced ethylene selectivity is generally associated with modifying ethylene adsorption strength and/or changes to hydride formation. Inorganic and organic selectivity modifiers (i.e., species adsorbed onto Pd particle surface) have also been shown to enhance ethylene selectivity. Inorganic modifiers such as TiO change Pd ensemble size and modify ethylene adsorption strength whereas organic modifiers such as diphenylsulfide are thought to create a surface template effect which favours acetylene adsorption with respect to ethylene. A number of metals and synthetic approaches have been explored to prepare Pd bimetallic catalysts. Examples where enhanced selectivity is observed are generally associated with decreased Pd ensemble size and/or hindering of the ease with which an unselective hydride phase is formed for Pd. A final class of bimetallic catalysts are discussed where Pd is not thought to be the primary reaction site but merely acts as a site where hydrogen dissociation and spillover occurs onto a second metal (Cu or Au) where the reaction takes place more selectively.

关键词： acetylene ethylene selective hydrogenation palladium bimetallic