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The synergic effects of highly selective bimetallic Pt-Pd/SAPO-41 catalysts for the n-hexadecane hydroisomerization

Frontiers of Chemical Science and engineering 2021年第5期15卷 1111-1124页

作者： Guozhi Jia Chunmu Guo Wei Wang Xuefeng Bai Xiaomeng Wei Xiaofang Su Tong Li Linfei Xiao Wei Wu National Center for International Research on Catalytic Technology Key Laboratory of Functional Inorganic Material Chemistry(Ministry of Education)Key Laboratory of Chemical Engineering Process&Technology for High-efficiency ConversionCollege of Heilongjiang ProvinceSchool of Chemistry and Material SciencesHeilongjiang UniversityHarbin150080China

The hydroisomerization of n-hexadecane over Pt-Pd bimetallic catalysts is an effective way to produce clean fuel *** work reports a useful preparation method of bimetallic bifunctional catalysts by a co-impregnation or sequential impregnation ***,monometallic catalysts with loading either Pt or Pd are also prepared for *** effects of the metal species and impregnation order on the characteristics and catalytic performance of the catalysts are *** catalytic test results indicate that the maximum iso-hexadecane yield over different catalysts increases as follows:Pt/silicoaluminophosphate SAPO-41

关键词： SAPO-41 molecular sieve Pt-Pd bimetallic site bifunctional catalysts n-hexadecane hydroisomerization

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Dark features evolution and inhibition mechanism of optical diamond thick film growth by MPCVD

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Ceramics International 2025年

作者： Chan, Siyi Huang, Ke Tu, Juping Yang, Zhiliang Zheng, Liping Liu, Peng An, Kang Li, Haixia Liu, Jinlong Chen, Liangxian Wei, Junjun Li, Chengming Institute for Advanced Materials and Technology University of Science and Technology Beijing Beijing100083 China College of Mechanical and Material Engineering North China University of Technology Beijing100144 China Institute of Process Engineering Chinese Academy of Science Beijing100190 China

Optical diamond materials exhibit exceptional optical properties, making them critical for applications such as infrared optical windows, microwave windows, and laser windows. These applications not only require diamond films to have high quality but also demand a large thickness to ensure sufficient strength. However, the appearance of dark features within the diamond is one of the key factors limiting its optical performance, especially in optical-grade diamond thick films. This work focuses on studying the variation in crystal structure during the growth of polycrystalline diamond thick films, aiming to mitigate the trend of quality degradation with increasing film thickness. It was found that diamond thick films deposited by microwave plasma chemical vapor deposition (MPCVD) exhibit significant quality stratification. Layered X-ray diffraction (XRD) and electron backscatter diffraction (EBSD) analysis of thick diamond samples revealed that, as the diamond film thickness increased, particularly when it reached 1200 μm or more, the content of dark features in the film significantly increased. Strong competitive growth occurred between grains, leading to the formation of grain clusters. This phenomenon is likely caused by the rough surfaces (such as depressions or steps) providing higher local activation energy when columnar grains grow to a certain height. Additionally, large-angle grain boundaries between columnar grains concentrate crystal defects, triggering penetrating twins and secondary nucleation. The formed small grains can become secondary grains, competing with the original grains during growth, inevitably introducing voids and low-quality diamond phases. To address this issue, a stepwise growth method was proposed, which refines the grains on the growth surface and reduces the density of dark features, ultimately achieving high-quality thick diamond films with thickness of 1.8 mm and a transmittance of 68.32 % at a wavelength of 10.6 μm. © 2025 Elsevier

关键词： Grain boundaries

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Analysis of mechanical properties of 3D printed metallic specimens of aluminum (CL31) bronze (CL80) material manufactured at varying laser scanning speed

Analysis of mechanical properties of 3D printed metallic spe...

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2022 International Conference on material Science, Mechanics and technology, ICMMT 2022

作者： Vashist, V. Oldal, I. Szakal, Z. Doctoral School of Mechanical Engineering Hungarian University of Agriculture and Life Sciences Gödöllo Hungary Material Sciences and Industrial Process Department Institute of Technology Hungarian University of Agriculture and Life Sciences Gödöllo Hungary

In our research work, we analyzed the mechanical properties of 3D-printed metallic specimens of aluminium bronze material. In our evaluation, we had five groups of specimens, manufactured at different laser scanning speeds. In total, we had 25 specimens for which we examined various parameters like ultimate tensile strength, engineering yield point, relative strain, and hardness. Results showed that specimens prepared with a lower laser scanning speed of 300mm/s showed the lowest tensile strength. The tensile strength increased with increasing laser scan speed and the highest tensile strength was attained by specimens of the fourth group that were produced at a laser scanning speed of 500mm/s. The relative strain of specimens also increased with the increasing scan speed of the laser. The Brinell hardness test also showed an elevation in hardness values with increasing laser scan speeds. © Published under licence by IOP Publishing Ltd.

关键词： Bronze

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Major challenges and recent advances in characterizing biomass thermochemical reactions

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Resources Chemicals and materials 2024年第2期3卷 146-158页

作者： Zhennan Han Junrong Yue Xi Zeng Jian Yu Fang Wang Yu Guan Xuejing Liu Fu Ding Liangliang Fu Xin Jia Xingfei Song Chao Wang Yanbin Cui Lei Shi Kangjun Wang Vladimir Zivkovic Dingrong Bai Guangwen Xu Key Laboratory on Resources Chemicals and Material of Ministry of Education Shenyang University of Chemical TechnologyShenyang 110142China The State Key Laboratory of Multi-phase Complex System Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Ecology and Environment Beijing Technology and Business UniversityBeijing 100048China School of Engineering Newcastle UniversityNewcastle Upon Tyne NE17RUUnited Kingdom

Thermochemical conversions are pathways for biomass utilization to produce various value-added energy and chemical products. For the development of novel thermochemical conversion technologies, an accurate understanding of the reaction performance and kinetics is essential. Given the diversity of the thermal analysis techniques, it is necessary to understand the features and limitations of the reactors, ensuring that the selected thermal analysis reactor meets the specific need for reaction characterization. This paper provides a critical overview of the thermal analysis reactors based on the following perspectives: 1) gas flow conditions in the reactor, 2) particle’s external and internal heat and mass transfer limitations, 3) heating rate, 4) temperature distribution, 5) nascent char production and reaction, 6) liquid feeding and atomization, 7) simultaneous sampling and analyzing of bed materials, and 8) reacting atmosphere change. Finally, prospects and future research directions in the development of analysis techniques are proposed.

关键词： Biomass Thermal analysis Quick heating Thermochemical reaction Reaction kinetics

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Effect of Al2O3/SiO2 micro-stacked composite coatings on the high-temperature performance of AISI 304 steel

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Ceramics International 2025年

作者： Ma, Jing Liu, Shuai-ze Chang, Xu Feng, Zhi-hao Li, Jian-hui Wang, Jian-gang Fan, Ming-qiang Hebei Short Process Steelmaking Technology Innovation Center School of Material Science and Engineering Hebei University of Science and Technology Hebei Shijiazhuang050018 China HBIS Group Technology Research Institute Hebei Shijiazhuang052165 China

Al2O3/SiO2 micro-stacked composite coatings with varying deposition sequences were fabricated on AISI 304 stainless steel to enhance their performance for applications exceeding 850 °C. Single coatings of Al2O3 and SiO2, as well as Al2O3-SiO2 (A-S) mixed coating, were prepared for comparative analysis. After 100 h of oxidation treatment at 900 °C, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy spectrum analysis (EDS)were used to investigate their high-temperature performance. The results demonstrated that all coatings effectively enhanced the high-temperature performance of stainless steel. The antioxidant properties of the coatings were ranked: coatings with SiO2 applied first (SSA, SAS) > coatings with Al2O3 applied first (ASA, AAS) > single coatings (AAA, SSS), revealing that the deposition sequences significantly effected the high-temperature performance of coatings. The combination of Al2O3 and SiO2 facilitates the formation of a more protective composite oxide, exhibiting complementary high-temperature antioxidant properties. The low mass gain of the A-S mixed coating and its high oxidation spallation indicate limited improvement in the antioxidant properties. A partial metallurgical bond layer has formed in the interface of coating/substrate for micro-stacked composite thin coatings with SiO2 applied first, which contributes to lower oxidation spallation thus the better oxidation resistance. The SAS micro-stacked composite thin coating demonstrated the best high temperature oxidation resistance, with mass gain and oxidation spallation of 41.2 % and 29.9 % respectively compared to those of the blank stainless steel sample. © 2025

关键词： Spalling

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High-entropy ceramics:Present status,challenges,and a look forward

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Journal of Advanced Ceramics 2021年第3期10卷 385-441页

作者： Huimin XIANG Yan XING Fu-zhi DAI Hongjie WANG Lei SU Lei MIAO Guojun ZHANG Yiguang WANG Xiwei QI Lei YAO Hailong WANG Biao ZHAO Jianqiang LI Yanchun ZHOU Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing 100076China New Energy Technology Engineering Laboratory of Jiangsu Province Nanjing University of Posts and TelecommunicationsNanjing 210023China State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an 710049China Guangxi Key Laboratory of Information Materials Guangxi Collaborative Innovation Center of Structure and Property for New Energy and MaterialSchool of Material Science and EngineeringGuilin University of Electronic TechnologyGuilin 541004China Institute of Functional Material College of Material Science and EngineeringDonghua UniversityShanghai 201620China Institute of Advanced Structure Technology Beijing Institute of TechnologyBeijing 100081China College of Metallurgy and Energy North China University of Science and TechnologyTangshan 063210China College of Material Science and Engineering Shenzhen UniversityShenzhen 518060China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001China Henan Key Laboratory of Aeronautical Materials and Application Technology School of Material Science and EngineeringZhengzhou University of AeronauticsZhengzhou 450046China National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology CAS Key Laboratory of Green Process and EngineeringInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China

High-entropy ceramics (HECs) are solid solutions of inorganic compounds with one or more Wyckoff sites shared by equal or near-equal atomic ratios of multi-principal *** in the infant stage,the emerging of this new family of materials has brought new opportunities for material design and property *** from metals,the diversity in crystal structure and electronic structure of ceramics provides huge space for properties tuning through band structure engineering and phonon *** from strengthening,hardening,and low thermal conductivity that have already been found in high-entropy alloys,new properties like colossal dielectric constant,super ionic conductivity,severe anisotropic thermal expansion coefficient,strong electromagnetic wave absorption,etc.,have been discovered in *** a response to the rapid development in this nascent field,this article gives a comprehensive review on the structure features,theoretical methods for stability and property prediction,processing routes,novel properties,and prospective applications of *** challenges on processing,characterization,and property predictions are also ***,future directions for new material exploration,novel processing,fundamental understanding,in-depth characterization,and database assessments are given.

关键词： high-entropy ceramics(HECs) processing structure properties applications

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State-of-the-art evolution of g-C_(3)N_(4)-based photocatalytic applications:A critical review

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Chinese Journal of Structural Chemistry 2024年第12期43卷 113-129页

作者： Yanghanbin Zhang Dongxiao Wen Wei Sun Jiahe Peng Dezhong Yu Xin Li Yang Qu Jizhou Jiang School of Environmental Ecology and Biological Engineering School of Chemistry and Environmental EngineeringKey Laboratory of Green Chemical Engineering Process of Ministry of EducationEngineering Research Center of Phosphorus Resources Development and Utilization of Ministry of EducationNovel Catalytic Materials of Hubei Engineering Research CenterWuhan Institute of TechnologyWuhan430205PR China Key Laboratory of Material Chemistry for Energy Conversion and Storage Ministry of EducationSchool of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan430074PR China College of Forestry and Landscape Architecture South China Agricultural UniversityGuangzhou510642PR China Key Laboratory of Functional Inorganic Materials Chemistry(Ministry of Education) School of Chemistry and Materials ScienceInternational Joint Research Center for Catalytic TechnologyHeilongjiang UniversityHarbin150080PR China

g-C_(3)N_(4)is a promising non-metallic photocatalyst recognized for its unique structural and physicochemical *** reviews have addressed g-C_(3)N_(4)-based photocatalysis;however,the rapid progress in big data and artificial intelligence has significantly accelerated the design,synthesis,and optimization of these *** learning,theoretical simulations,and advanced in-situ characterization techniques have deepened our understanding of their photocatalytic *** review critically evaluates advancements in g-C_(3)N_(4)-based photocatalysts over the last two to three years,focusing on strategies to improve photogenerated charge sepa-ration,expand light absorption,and enhance stability and catalytic *** discusses cutting-edge in-situ characterization methods alongside machine learning approaches for predicting and optimizing applications in photocatalytic H_(2)evolution,CO_(2)reduction,pollutant degradation,H_(2)O_(2)production,and nitrogen ***,it proposes prospective strategies for further enhancing the performance of g-C_(3)N_(4)-based photocatalysts,aiming to guide the design of high-performance two-dimensional carbon-based photocatalysts.

关键词： g-C_(3)N_(4) Photocatalysis Enhancement strategies In-situ characterization Theoretical simulations

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Stability and thermal conductivity of different nano-composite material prepared for thermal energy storage applications

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South African Journal of Chemical engineering 2022年 39卷 72-89页

作者： Ibrahim, Sarmad I. Ali, Ahmed H. Hafidh, Sanaa A. Chaichan, Miqdam T. Kazem, Hussein A Ali, Jarinah Mohd Isahak, Wan Nor Roslam Alamiery, Ahmed Material Eng. Department University of Technology - Iraq Energy and Renewable Energies Technology Center University of Technology – Iraq Faculty of Engineering Sohar University Sohar Oman Department of Chemical and Process Engineering Faculty of Engineering and Built Environment University Kebangsaan Malaysia (UKM) P.O. Box: 43000 Bangi Selangor Malaysia

The interest in solar energy applications doubles due to the necessities of the stage, and because of it, the interest in heat storage materials expands, the most important of which is paraffins. Paraffins suffer from low thermal conductivity, so many researchers have added nanomaterials that improve this property. In this study, nano-TiO2 and MgO and a 50% mixture of each were added to the Iraqi paraffin. The addition of nanoparticles caused the paraffin to change color from brown to white with the change of absorbance and transmittance properties. The density, viscosity, and heat capacity of the products increased slightly. The thermal conductivity of the products improved and the highest value obtained was 24.92%. The melting and solidification points decreased by one degree Celsius for the case of addition of nano-TiO2 and MgO and by 2 °C for the case of addition of the hybrid nanoparticles. Besides, the period of phase change of the products decreased. The nano-paraffin mixture showed high stability for more than 90 days and it is preferable to repeat the mixing process every 6 months to ensure this property. The study concludes that the addition of hybrid nano-TiO2 and MgO to Iraqi paraffin is suitable for solar energy applications. © 2021 The Author(s)

关键词： Hybrid nanoparticles Melting-solidification cycles MgO Paraffin Thermal conductivity TiO2

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Evolution of Steel Chemistry and Cleanliness During RH Degassing process

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Iron and Steel technology 2023年第6期20卷 170-179页

作者： Garg, Diti Sahoo, P.P. Tripathy, P.K. Ghosh, Biswajit Shah, Hitesh Hasmukhrai Viswanathan, N.N. Kumar, Deepoo Tech. Steel and Casting Technology Tata Steel Ltd. JH Jamshedpur India R&D Tata Steel Ltd. JH Jamshedpur India Raw Material Technology Group Process Technology Tata Steel Ltd. JH Jamshedpur India Technology Tata Steel Ltd. JH Jamshedpur India LD2 and Slab Caster Tata Steel Ltd. JH Jamshedpur India Department of Metallurgical Engineering and Materials Science Indian Institute of Technology – Bombay MH Mumbai India

Ultralow-carbon steels produced by the converter are further decarburized, deoxidized and alloyed in a RH degasser. Timing and the amount of alloying additions/blowing can significantly affect the process efficiency and steel quality. Kinetic models can be used to study decarburization, mixing of alloys, chemistry and cleanliness evolution during the process. In this work, steel and slag samples are collected during the RH degassing process. A kinetic model for the RH degassing process is developed using the macroprocessing feature in FactSage 8.1. The measured chemistry of steel and slag and inclusion analysis of the steel samples is used to estimate the model parameters. © Association for Iron & Steel technology.

关键词： Slags

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Giant tunneling magnetoresistance in insulated altermagnet/ferromagnet junctions induced by spin-dependent tunneling effect

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Physical Review B 2024年第13期110卷 134437页

作者： Fangqi Liu Zhenhua Zhang Xiaojuan Yuan Yong Liu Sicong Zhu Zhihong Lu Rui Xiong Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education School of Physics and Technology The State Key Laboratory of Refractories and Metallurgy School of Material Science and Technology Hubei Province Key Laboratory of Systems Science in Metallurgical Process Department of Mechanical Engineering

The nondegenerate energy bands along a specific path of altermagnet enable the realization of magnetic tunnel junctions (MTJs) with high tunnel magnetoresistance (TMR). Herein, we propose a MTJ based on insulated altermagnet/ferromagnetic MTJ−MnF2/CrO2. In addition to effectively simplifying the device configuration, high TMR is attained in the [110] and [111] crystal directions due to the spin-dependent tunneling effect in the real space of MnF2. The increase in the thickness of the MnF2 layer leads to an increase in electron spin filtering efficiency (SFE). When the thickness of the MnF2 layer is three layers, the SFE is as high as 85.65% and the TMR is as high as 104%. In addition, we find that the interface type has a significant impact on the magnetoresistance performance of the tunnel junction. Compared with F interface, the O interface leads to a further increase in the SFE of MnF2 (99.56%) and conductance of MTJ, and thus a significant enhancement of the TMR (up to 105%). The analysis of electronic states in real space reveals that the coordination of oxygen atoms with magnetic atoms in the current direction gives rise to the endowed electronic states and an increase in spin polarizability in the vicinity. The results provide insight into the development of ultrafast and efficient spintronic devices with altermagnet.

关键词： Antiferroelectricity Electrical properties First-principles calculations Magnetism Spintronics

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