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Ce-and La-doped polymetallic layered double hydroxides for enhanced oxygen evolution reaction performance at high current density

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Science China Chemistry 2024年第8期67卷 2586-2598页

作者： Rinel R.Kimaka P. Ping Wang Miao He Senyao Meng Jiasai Yao Huawei Li Cheng Yang Zhenxing Li state key laboratory of Heavy Oil processing College of New Energy and MaterialsChina University of Petroleum(Beijing)Beijing 102249China

Polymetallic layered double hydroxides are promising cost-effective catalysts for the oxygen evolution reaction(OER) due to their versatile anionic and cationic tunability. Nevertheless, several challenges persist, notably, issues related to low electrical conductivity, poor catalytic activity, and stability, especially at high current density. Herein, we report the design of Ce-and Ladoped Co Ni Fe-layered double hydroxide(Ce La Co Ni Fe-LDH) nanosheets through a facile and scalable in situ self-assembly strategy that displays enhanced OER activity. Experimental and theoretical investigations provide insights into the impact of Ceand La-doping by comparing Ce Co Ni Fe-LDH, La Co Ni Fe-LDH, and pristine Co Ni Fe-LDH, all synthesized using the same methodology. These results reveal that doping Ce^(3+)and La^(3+)into Co Ni Fe-LDH substantially improves its electronic structure,resulting in enhanced conductivity, more oxygen vacancies(Vo), electron interaction, and active site formation. Consequently,significantly reduced overpotentials of 175, 314, and 424 m V at 10, 100, and 500 m A cm^(-2), respectively, and a highly stable current density of 120 h in 1 M KOH were achieved. Notably, these performance metrics surpass those of unmodified LDHs and are competitive with many lanthanide-doped transition metal-based LDH electrocatalysts, as well as noble metal catalysts like ruthenium catalysts. This work represents a pioneering effort in doping Ce^(3+)and La^(3+)ions into a functional Co Ni Fe-based electrocatalyst, offering inspiring OER performance and scalability potential.

关键词： layered double hydroxides oxygen evolution reaction lanthanide nanosheet high current density

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Simultaneously enhancing the strength and ductility of as-extruded AlN/AZ91 composites via nano-precipitation and pyramidal slip

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Journal of Materials Science & Technology 2024年第5期172卷 240-254页

作者： Bin Zhang Yunxia Sun Tuo Liang Yunzhen Li Tian Li Jingchao Wang Ruiru Cai Changlin Yang state key laboratory of Solidification processing Northwestern Polytechnical UniversityXi’an 710072China

Age hardening is often used to optimize the mechanical properties of as-deformed Mg-based materials in industry,whereas the improvement of strength is usually accompanied by the significant loss of ductility,which hinders the application of Mg-based materials in structural *** the present work,high strength-ductility synergy(the yield strength of 263±9 MPa,ultimate tensile strength of 398±7 MPa and elongation to fracture of 34%±1%)was realized in as-extruded AlN/AZ91 composites after optimiz-ing aging *** characterization shows that AlN particles induced a large number of geometrically necessary dislocations around the AlN/Mg interface during extrusion,which decreased the nucleation barrier and provided more heterogeneous nucleation sites forγ-Mg 17 Al 12 continuous ***,95%of residual dislocations in as-extruded AlN/AZ91 composites were annihilated dur-ing peak-aging,suppressing the growth and coarsening of continuous ***,high density of nano-sizedγ-Mg 17 Al 12 continuous precipitates was produced in as-extruded AlN/AZ91 composites af-ter *** tension,gliding dislocations bypassed sphericalγ-Mg 17 Al 12 nano-precipitates by Orowan looping rather than cutting mechanism,which induced a strong block on dislocation *** high yield strength was mainly attributed to the high density of non-shearableγ-Mg 17 Al 12 nano-precipitates with spherical morphology,which was different from other Mg-Al-based *** results of texture evolution and slip trace analysis demonstrated that the suppression of extension twinning and less basal slip was due to the enhanced activity of pyramidalc+aslip in as-extruded AlN/AZ91 com-posites after peak-aging during the room temperature tension,meanwhile,the dislocation density of as-extruded AlN/AZ91 composites was significantly decreased during peak-aging,then higher elongation to fracture was achieved.

关键词： Magnesium matrix composites Mechanical properties Precipitation Deformation mechanisms Non-basal slip

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Highly Efficient Broadband Achromatic Microlens Design Based on Low-Dispersion Materials

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Engineering 2024年第7期38卷 194-200页

作者： Xueqian Wang Chuanbao Liu Feilou Wang Weijia Luo Chengdong Tao Yuxuan Hou Lijie Qiao Ji Zhou Jingbo Sun Yang Bai Beijing Advanced Innovation Center for Materials Genome Engineering Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China School of Materials and Engineering University of Science and Technology BeijingBeijing 100083China state key laboratory of new ceramics and fine processing School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

Metalenses with achromatic performance offer a new opportunity for high-quality imaging with an ultracompact configuration;however,they suffer from complex fabrication processes and low focusing *** this study,we propose an efficient design method for achromatic microlenses on a wavelength scale using materials with low dispersion,an adequately designed convex surface,and a thickness profile *** taking into account the absolute chromatic aberration,relative focal length shift(FLS),and numerical aperture(NA),microlens with a certain focal length can be realized through our realized map of geometric ***,the designed achromatic microlenses with low-dispersion fused silica were fabricated using a focused ion beam,and precise surface profiles were *** fabricated microlenses exhibited a high average focusing efficiency of 65%at visible wavelengths of 410-680 nm and excellent achromatic capability via white light ***,the design exhibited the advantages of being polarization-insensitive and *** results demonstrate the effectiveness of our proposed achromatic microlens design approach,which expands the prospects of miniaturized optics such as virtual and augmented reality,ultracompact microscopes,and biological endoscopy.

关键词： Broadband achromatic focusing Metamaterials Low dispersion materials Visible wavelength Microlenses

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Effect of operating conditions on the performance of riser reactor for oxidative coupling of methane Author links open overlay panel

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Particuology 2024年第8期91卷 235-248页

作者： Min Cai Shuangzhu Kong Mengxi Liu Chunxi Lu state key laboratory of Heavy Oil processing China University of PetroleumBeijing102249China

Oxidative coupling of methane(OCM)is characterized by high temperature and strong heat released.A riser reactor is designed for the OCM process to improve gas-solid contacting and heat *** work illustrates the effect of hydrodynamic conditions and feed gas composition on the performance of an OCM riser *** findings suggest that oxidative reactions predominantly occur within the acceleration zone and developed flow ***,at the low superficial gas velocity accompanied by a high solid circulating rate,the C_(2)yield initially increases in the acceleration zone,followed by a decrease in the developed flow zone and deceleration *** optimal operating conditions are a specific region corresponding to the solids holdup ranges from 0.015 to ***,the C_(2)yield can be elevated using an appropriate feed mixture.

关键词： Oxidative coupling of methane Riser Hydrodynamics Solids holdup

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Morphology effect on catalytic performance of ebullated-bed residue hydrotreating over Ni-Mo/Al_(2)O_(3)catalyst:a kinetic modeling study

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Green Chemical Engineering 2024年第1期5卷 60-67页

作者： Zhe Liu Juncong Yuan Zongzhuang Sun Xiang Feng Yibin Liu Huihong Zhu Chong Peng Chaohe Yang state key laboratory of Heavy Oil processing China University of PetroleumQingdao266580China Dalian Research Institute of Petroleum and Petrochemicals SINOPECDalian116045China state key laboratory of fine Chemicals Dalian University of TechnologyDalian116024China

Upgrading of vacuum residue is of prime industrial significance due to the increasing demand for light *** the effect of catalyst morphology on vacuum residue hydrotreating performance by kinetic modeling is therefore of great ***,kinetic analysis of hydrodemetallization(HDM)and hydrodeconradsoncarbon-residue(HDCCR)performances on industrial Ni-Mo/Al_(2)O_(3)catalysts with spherical and cylindrical morphologies in ebullated-bed were evaluated for more than 1600 *** was found that the percentage of light impurities easier to be removed on spherical catalysts were 78.20%and 39.43%in HDM and HDCCR reactions,respectively,higher than 65.20%and 17.50%on cylindrical *** suggests that catalyst morphology affects the impurity removal ability and the impurity properties,resulting in better hydrotreating performance of spherical *** work not only combines catalyst morphology with impurity removal capability through kinetic modeling,but also provides new insights into the design of efficient hydrotreating catalysts.

关键词： Morphology effect Kinetic analysis Vacuum residue Hydrotreating

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Study on metal recovery process and kinetics of oxidative leaching from spent LiFePO_(4)Li-batteries

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Chinese Journal of Chemical Engineering 2024年第4期68卷 94-102页

作者： Xiaoming Zhang Wen Xie Xiaolei Zhou Wenjie Zhang Jiawei Wen Xin Wang Guoyong Huang Shengming Xu College of new Energy and Materials China University of PetroleumBeijing 102249China state key laboratory of Heavy Oil processing College of Chemical EngineeringChina University of PetroleumBeijing 102249China Beijing Spacecrafts Beijing 100094China Ganfeng Lithium Group Co. Ltd.Xinyu 338000China Institute of Nuclear and new Energy Technology Tsinghua UniversityBeijing 100084China Beijing key laboratory of fine ceramics Tsinghua UniversityBeijing 100084China

A green environmental protection and enhanced leaching process was proposed to recover all elements from spent lithium iron phosphate(LiFePO_(4)) lithium *** order to reduce the influence of Al impurity in the recovery process,NaOH was used to remove *** impurity removal,the spent LiFePO_(4) cathode material was used as raw material under the H_(2)SO_(4) system,and the pressure oxidation leaching process was adopted to achieve the preferential leaching of *** E-pH diagram of the Fe-P-Al-H_(2)O system can determine the stable region of each element in the recovery process of spent LiFePO_(4)*** the optimal conditions(500 r·min^(-1),15 h,363.15 K,0.4 MPa,the liquid-solid ratio was 4:1 ml·g^(-1)and the acid-material ratio was 0.29),the leaching rate of Li was 99.24%,Fe,Al,and Ti were 0.10%,2.07%,and 0.03%,*** Fe and P were precipitated and recovered as FePO_(4)·2H_(2)*** kinetic analysis shows that the process of high-pressure acid leaching of spent LiFePO_(4) materials depends on the surface chemical *** the life cycle assessment(LCA)of the spent LiFePO_(4) whole recovery process,eight midpoint impact categories were selected to assess the impact of recovery *** results can provide basic environmental information on production process for recycling industry.

关键词： Spent LiFePO_(4)Li-batteries Oxidative leaching Kinetic study Life cycle assessment

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A Study on the Impact of Chemical Structure on the Evolution of Aggregate Structure in Fiber-shaped High Density Polyethylene Vitrimer

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Chinese Journal of Polymer Science 2024年第10期42卷 1557-1565页

作者： Bing Wang Yuan-Chu Gao Hai Wang Hui Niu state key laboratory of fine Chemicals School of Chemical EngineeringDalian University of Technology

Vitrimers have emerged as a prominent research area in the field of polymer materials. Most of the studies have focused on synthesizing polymers with versatile dynamic crosslinking structures, while the impact of chemical structure on aggregate structure of vitrimers, particularly during polymer processing, remains insufficiently investigated. The present study employed commercial maleic anhydride-grafted-high density polyethylene (M-g-HDPE) as the matrix and hexanediol as the crosslinker to facilely obtain fiber-shaped HDPE vitrimers through a reaction extrusion and post-drawing process. Through chemical structure characterization, morphology observation, thermal and mechanical properties investigation, as well as aggregate structure analysis, this work revealed the influence of dynamic bonds on the formation of aggregate structures during fiber-shaped vitrimers processing. A small amount of dynamic bonds in HDPE restricts the motion of PE chain during melt-extruding and post-drawing, resulting in a lower orientation of the PE chains. However, lamellar growth and fibril formation during post-drawing at high temperature are enhanced to some extent due to the competition between dynamic bond and chain relaxation. The uneven morphology of fibershaped HDPE vitrimers can be attributed to the stronger elastic effect brought by dynamic bonding, which plays a more dominant role in determining the mechanical properties of fiber-shaped vitrimers compared to aggregate *** Vitrimers have emerged as a prominent research area in the field of polymer *** of the studies have focused on synthesizing polymers with versatile dynamic crosslinking structures,while the impact of chemical structure on aggregate structure of vitrimers,particularly during polymer processing,remains insufficiently *** present study employed commercial maleic anhydride-grafted-high density polyethylene (M-g-HDPE) as the matrix and hexanediol as the crosslinker to facile

关键词： Aggregate structures Fiber-shaped High density polyethylene vitrimer Transesterification reaction

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Enhancement of–OH content on mechanical properties of antiperovskite solid electrolytes

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Nano Research 2024年第7期17卷 6139-6146页

作者： Zunqiu Xiao Huaying Wang Ningyuan Cai Yutong Li Kejia Xiang Wei Wei Tao Ye Zhongtai Zhang Shitong Wang Zilong Tang state key Lab of new ceramics and fine processing School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China College of new Energy Advanced Chemical Engineering and Energy Materials Research CenterChina University of Petroleum(East China)Qingdao 266580China Department of Nuclear Science and Engineering Massachusetts Institute of TechnologyCambridgeMA 02139USA

All-solid-state batteries,renowned for their enhanced safety and high energy density,have garnered broad *** solid electrolytes are highly anticipated for their balanced ***,their high Young’s modulus and inadaptability to volume change during cycling lead to poor contact and eventual battery *** this work,Young’s modulus of Li_(1+x)(OH)_(x)Cl samples is lowered to a level comparable to that of sulfide by regulating the–OH *** the–OH content increases,Young’s modulus of Li_(1+x)(OH)_(x)Cl samples decreases *** may be due to the local aggregation of–OH groups,forming cavities similar to LiOH structure,which reduces the bonding of the *** the premise of high Li-ion conductivity and electrochemical stability,the lowered Young’s modulus improves the contact between the solid electrolyte and the electrodes,forming a strong and stable interfacial layer,thereby improving interfacial and cycling *** symmetrical lithium metal cell shows excellent cycle performance of 600 h,and the assembled LiFePO_(4)|Li_(2.4)(OH)1.4Cl|Li cell shows significantly enhanced cycling endurance with 80%capacity retention after 150 *** work not only emphasizes the crucial importance of Young’s modulus in improving interface issues but also offers innovative approaches to advance the mechanical properties of solid electrolytes.

关键词： mechanical properties -OH content anti-perovskite solid electrolytes Li-ion batteries

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Acoustic characterization of hydrate formation and decomposition in clay-bearing sediments

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Petroleum Science 2024年第4期21卷 2830-2838页

作者： Yi-Jian Zhu Xiao-Mei Yang Xing Huang Hao Li Xiao-Hui Wang Yi-Fei Sun Peng Xiao Chang-Yu Sun Guang-Jin Chen state key laboratory of Heavy Oil processing College of Chemical Engineering and Environment China University of Petroleum

Understanding the acoustic characteristics of hydrates in various sediments is crucial for hydrate resource detection and safe and efficient exploitation, as hydrate occurrence patterns vary greatly in different sediments. In this work, sediments with different bentonite contents, water saturations, and types were prepared to investigate the characteristics of P-wave velocity(reflecting the magnitude of hydrate saturation in the sediment) and amplitude(reflecting the degree of hydrate-sediment cementation) during hydrate formation and depressurization. During hydrate formation, the P-wave velocity and amplitude have similar trends. As clay content increases, the P-wave velocity increase rates quickened. On the other hand, the increased rate of P-wave velocity slows down with the increase of water saturation in the clay-bearing sediments. Comparing various types of sediment shows that the water absorption and swelling of bentonite reduce the pore space, speeding up the cementation of the hydrate with the sediment and increasing P-wave velocity at a faster rate. Correspondence between P-wave velocity and hydrate saturation is strongly related to sediment type, clay content, and water *** rapidly decreasing amplitude in the early stage of hydrate depressurization indicates that hydrate in clay-bearing sediments is weakly cemented to the sediments, which is prone to stratigraphic *** findings of this study offer guidance for hydrate resource assessments in clay-bearing sediments as well as geologic risk estimations during hydrate mining.

关键词： gas hydrate bentonite illite P-wave velocity amplitude

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Fabrication of highly effective electrodes for iron chromium redox flow battery

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Nano Research 2024年第5期17卷 3988-3996页

作者： Yingchun Niu Chao Guo Yinping Liu Guangfu Wu Tianhang Zhou Fangang Qu Ziji Yang Ali Heydari Chunming Xu Quan Xu state key laboratory of Heavy Oil processing China University of Petroleum(Beijing)Beijing 102249China

Iron-chromium redox flow batteries(ICRFBs)have emerged as promising energy storage devices due to their safety,environmental protection,and reliable *** carbon cloth(CC),often used in ICRFBs as the electrode,provides a suitable platform for electrochemical processes owing to its high surface area and interconnected porous ***,the CC electrodes have issues,such as,insufficient electron transfer performance,which limits their industrial ***,we employed silicic acid etching to carve dense nano-porous structures on the surface of CC electrodes based on the favorable design of ICRFBs and the fundamental principles of electrode polarization *** a result,we developed a multifunctional carbon cloth electrode with abundant vacancies,notably enhancing the performance of the *** fabricated electrode showcased a wealth of defect sites and superior electronic transport properties,offering an extensive and effective reaction area for rapidly flowing *** an electrode compression ratio of 40%and the highest current density in ICRFBs so far(140 mA·cm^(-2)),the battery achieved the average energy efficiency of 81.3%,11.24%enhancement over the previously published ***,throughout 100 charge-discharge cycles,the average energy efficiency degradation was negligible(~0.04%),which has the potential to become the most promising candidate for large-scale and long-term electrochemical energy storage applications.

关键词： iron chromium redox flow battery electron carbon cloth defect site density functional theory(DFT)calculation

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