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面向碱性析氢反应的原子级优化Fe-Pt金属间化合物催化剂表面终结态探索

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Science Bulletin 2024年第8期69卷 1091-1099页

作者：梁庆孟繁玲李文文邹旭宋可心葛昕姜周刘玉华刘美琦李振宇董韬文陈中军张伟郑伟涛 Key Laboratory of Automobile Materials(Ministry of Education) School of Materials Science and EngineeringElectron Microscopy CenterInternational Center of Future ScienceJilin Provincial International Cooperation Key Laboratory of High-Efficiency Clean Energy MaterialsJilin UniversityChangchun 130012China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China

Controlling the atomic arrangement of elemental atoms in intermetallic catalysts to govern their surface and subsurface properties is a crucial but challenging endeavor in electrocatalytic reactions.In hydrogen evolution reaction(HER),adjusting the d-band center of the conventional noble-metallic Pt by introducing Fe enables the optimization of catalytic performance.However,a notable gap exists in research on the effective transition from disordered Fe/Pt alloys to highly ordered intermetallic compounds(IMCs)such as FePt_(3)in the alkaline HER,hampering their broader application.In this study,a series of catalysts FePt_(3-x)H(x=5,6,7,8 and 9)supported on carbon nanotubes(CNTs)were synthesized via a simple impregnation method,along with a range of heat treatment processes,including annealing in a reductive atmosphere,to regulate the order degree of the arrangement of Fe/Pt atoms within the FePt_(3)catalyst.By using advanced microscopy and spectroscopy techniques,we systematically explored the impact of the order degree of FePt_(3)in the HER.The as-prepared FePt_(3)-8H exhibited notable HER catalytic activity with low overpotentials(η=37 mV in 1.0 mol L^(-1)KOH)at j=10 mA cm^(-2).The surface of the L1_(2)FePt_(3)-8H catalyst was demonstrated to be Pt-rich.The Pt on the surface was not easily oxidized due to the unique Fe/Pt coordination,resulting in significant enhancement of HER performance.

关键词： intermetallic Hydrogen evolution reaction Surface Catalyst

Off-stoichiometry-guided design of high-strength chemically complex intermetallic-based alloys with outstanding ductility

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Journal of Materials Science & Technology 2023年第29期160卷 28-33页

作者： Bo Xiao Jixun Zhang Shaofei Liu Yilu Zhao Lianyong Xu C.T.Liu Tao Yang Department of Materials Science and Engineering Mechanical Behavior Division of Shenyang National Laboratory for Materials ScienceCity University of Hong KongHong KongChina Center for Advanced Nuclear Safety and Sustainable Development City University of Hong KongHong KongChina Hong Kong Institute for Advanced Study City University of Hong KongHong KongChina School of Materials Science and Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China School of Materials Science and Engineering Tianjin UniversityTianjin 300350China

1.Introduction The lasting drive for improved energy efficiency in power gen-eration encourages the innovative design of advanced structural materials with superb mechanical properties[1-6].Among these materials,ordered intermetallic alloys[7-9],as a unique class of metallic materials,have drawn increasing concern from both the scientific and industrial communities due to their intriguing high-temperature properties,strong chemical binding,and low atomic mobility[10,11].However,in light of the insufficient number of slip systems and/or intrinsically weak grain boundary(GB),they are usually brittle at ambient temperature,severely hindering their practical use in engineering systems[12].Previous studies reported that the change in alloy stoichiometry has a significant beneficial effect on the ductility of intermetallic alloys.For instance,Liu et al.

关键词： intermetallic ductility alloys

Single-phase high-entropy intermetallic compounds(HEICs): bridging high-entropy alloys and ceramics

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Science Bulletin 2019年第12期64卷 856-864页

作者： Naixie Zhou Sicong Jiang Timothy Huang Mingde Qin Tao Hu Jian Luo Department of Nanoengineering Program of Materials Science and EngineeringUniversity of CaliforniaSan DiegoCA 92093-0448USA Oerlikon Metco Inc. San DiegoCA 92121USA State Key Laboratory of High Performance and Complex Manufacturing School of Materials Science and EngineeringCentral South UniversityChangsha 410083China

High-entropy intermetallic compounds(HEICs)were fabricated by mechanical alloying and spark plasma sintering to fill a knowledge gap between the traditional high-entropy alloys(HEAs)and emerging highentropy ceramics(HECs).Notably,several four-or five-component equimolar aluminides,such as the B2-phase(Fe1/5 Co1/5 Ni1/5 Mn1/5 Cu1/5)Al,have been made into single-phase HEICs for the first time.Thermodynamic modeling and a reversible,temperature-dependent,phase-stability experiment suggest that such B2-phase HEICs are entropy-stabilized phases.The structure of these HEICs resembles that of HECs with high-entropy mixing of fo ur or five elements of nearly equal fractions in one and only one sublattice,but with significant(10%)anti-site defects(differing from typical HECs).A new phase stability rule for forming single B2-phase HEICs is proposed.Five additional HEICs of predominantly D022 phases have also been made.This study broadens the families of equimola r,single-phase,high-entropy materials that have been successfully fabricated.

关键词： High-entropy intermetallic compound Aluminide Phase stability High-entropy alloy High-entropy ceramic

Ab initio study of structural,electronic,thermo-elastic and optical properties of Pt3Zr intermetallic compound

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Chinese Physics B 2020年第4期29卷 405-414页

作者： Wahiba Metiri Khaled Cheikh Departement de Physique Facultedes SciencesUniversite 20 aout 1955-Skikda BP 26Route El-Hadaiek21000 SkikdaAlgeria Departement de Technologie Facultede TechnologieUniversite 20 aout 1955-Skikda BP 26Route El-Hadaiek21000 SkikdaAlgeria

Structural,elastic,electronic and optical properties of the Pt3Zr intermetallic compound are investigated using first principles calculations based on the density functional theory(DFT)within the generalized gradient approximation(GGA)and the local density approximation(LDA).The Pt3Zr compound is predicted to be of cubic L12 and hexagonal D024 structures.The calculated equilibrium ground-state properties(lattice parameters a and c,bulk modulus B and its pressure derivative B',formation enthalpy ΔH)of the Pt3Zr compound,for both cubic and hexagonal phases,show good agreement with the experimental results and other theoretical data.Elastic constants(C11,C12,C13,C33,C44,and C55)are calculated.The predicted elastic properties such as Young's modulus E and shear modulus GH,Poisson ratioν,anisotropic ratio A,Kleinman parameter ξ,Cauchy pressure(C12-C44),ratios B/C44 and B/G,and Vickers hardness Hv indicate the stiffness,hardness and ductility of the compound.Thermal characteristic parameters such as Debye temperature θD and melting temperature Tm are computed.Electronic properties such as density of states(DOS)and electronic specific heat γ are also reported.The calculated results reveal that the Fermi level is on the psedogap for the D024 structure and on the antibonding side for the L12 structure.The optical property functions(real partε1(ω)and imaginary part ε2(ω)of dielectric function),optical conductivity σ(ω),refraction index n(ω),reflectivity R(ω),absorption α(ω)and extinction coefficients k(ω)and loss function L(ω)are also investigated for the first time for Pt3Zr in a large gamme of energy from 0 to 70 eV.

关键词： density functional theory intermetallic density of states L12 D024 optical properties

Glass formation adjacent to the intermetallic compounds in Cu-Zr binary system

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Journal of Materials Science & Technology 2018年第4期34卷 605-612页

作者： Yinxiao Wang Jiahao Yao Yi Li Shenyang National Laboratory for Materials Science Institute of Metal research Chinese Academy of Sciences

On the contrary to the common belief that glass formation is unfeasible near terminal intermetallic com- pound due to fast crystallization kinetics, here we present our findings that bulk metallic glasses are readily formed near intermetallic compounds, far away from the traditional region of glass forming near eutectics. While the intermetallic compounds themselves are not possible glass formers, bulk metallic glasses can be quenched compositionally neighboring the intermetallic compounds as close as 0.5 at.%. Taking binary Cu-Zr as a model system, the phenomenon of two optimum glass forming compositions sandwiching the corresponding intermetallic compounds （Cu51 Zr14, CU10Zr7, CuZr, CuZr2 and Cu8Zr3） is observed consistently. This new scenario of＂intermetallic glass＂ is verified by the thermodynamic princi- ple that the alloy liquids neighboring the intermetallic compounds possess lower Gibbs free energy than that of the compounds themselves. Furthermore, the sluggish crystallization behavior of these liquids provides an additional kinetic explanation.

关键词： Metallic glass intermetallic Glass forming ability Crystallization kinetics

Selective hydrogenation of acetylene on SiO_2-supported Ni-Ga alloy and intermetallic compound

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Journal of Energy Chemistry 2019年第2期28卷 40-49页

作者： Lei Wang Fengxu Li Yanjun Chen Jixiang Chen Tianjin Key Laboratory of Applied Catalysis Science and Technology Department of Catalysis Science and EngineeringSchool of Chemical Engineering and TechnologyTianjin University

Ni/Si O_2 and bimetallic Ni_xGa/SiO_2 catalysts with different Ni/Ga atomic ratios(x = 10～2) were investigated for the selective hydrogenation of acetylene.It was found that Ni_xGa/SiO_2 showed higher selectivity to ethylene than Ni/Si O_2.This is attributed to the formation Ni-Ga alloy and Ni3 Ga intermetallic compound(IMC) where there was a charge transfer from Ga to Ni,which is favorable for reducing the adsorption strength and amount of ethylene on Ni atoms.As a result,the over-hydrogenation,the C–C bond hydrogenolysis and the polymerization were suppressed,and subsequently the selectivity to ethylene was enhanced.With the decrease of Ni/Ga atomic ratio,the activity and stability of the Ni_xGa/SiO_2 catalysts increased first and then decreased,while the ethylene selectivity tended to increase.Ni_5 Ga/SiO_2 exhibited the best performance.Under the conditions of 180 °C,0.1 MPa,and a reactant(1.0 vol% acetylene,5.0 vol% H_2 and 94 vol% N_2) with the space velocity of 36,000 m L h^(-1) g^(-1),the acetylene conversion maintained at 100% on Ni_5 Ga/SiO_2 during 120 h time on stream and the selectivity to ethylene was 75%～81%after reaction for 68 h.It was also found that the formation of Ni-Ga alloy and Ni_3 Ga IMC suppressed the incorporation of carbon to form NiCx,subsequently enhancing the catalyst stability.Additionally,with increasing the Ga content,the catalyst acid amount and strength tended to increase,which promoted the polymerization and carbon deposition and so the catalyst deactivation.

关键词： Selective hydrogenation Acetylene Ni-Ga alloy Ni3Ga intermetallic compound

Remarkably reducing carbon loss and H2 consumption on Ni–Ga intermetallic compounds in deoxygenation of methyl esters to hydrocarbons

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Journal of Energy Chemistry 2020年第2期29卷 194-208页

作者： Ning Zhao Ying Zheng Jixiang Chen Tianjin Key Laboratory of Applied Catalysis Science and Technology Department of Catalysis Science and EngineeringSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350China

Ni–Ga alloy(Ni/Ga atomic ratio of 8),Ni3Ga and Ni5Ga3 intermetallic compounds(IMCs)catalysts were prepared from Ni–Mg-Al-Ga layered double hydroxides(LDHs)for the deoxygenation of methyl esters to hydrocarbons.In the alloy and IMCs,the presence of Ga reduced the surface Ni atom density,and the charge transfer from Ga to Ni increased the electron density of Ni.In the deoxygenation of methyl laurate,the Ni catalyst gave a complete hydrogenolysis of methyl laurate to CH4at 330°C and 3.0 MPa,while the presence of Ga promoted the HDO pathway and suppressed C–C bond hydrogenolysis and methanation.The Ni5Ga3 catalyst exhibited the best desired performance.Even at 400°C,it gave the yield of C11 and C12 hydrocarbons of ~99%,and the selectivity to CH4(SCH4) was only 2.4%.In the deoxygenation of methyl octanoate and methyl palmitate,the Ni5Ga3 catalyst also gave the yield of hydrocarbons above95%.Reactivity evaluation and methyl propionate-TPD and TPSR results indicate that the C–OCH3 bond instead of the O–CH3 one was cleaved on both Ni and bimetallic Ni–Ga catalysts.It is highlighted that methanol,derived from the C–OCH3 bond hydrogenolysis,mainly decomposed to CO and H2 on IMCs,while it was converted to methane on metallic Ni and alloy.It is of great significance that H2 could be yielded from the methyl ester itself.In short,the utilization of Ni–Ga IMCs can effectively reduce carbon loss and H2 consumption,all of which are ascribed to the geometric and electronic effects of Ga.

关键词： Ni–Ga intermetallic compounds Methyl ester Decarbonylation/decarboxylation Hydrodeoxygenation C–C bond hydrogenolysis Methanation

Growth rate and composition of directionally solidified intermetallic TiAl–Nb alloys with different solidification conditions

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Rare Metals 2016年第1期35卷 54-64页

作者： Li-Wei Zhang Jun-Pin Lin Xiang-Jun Xu Jian-Ping He Xian-Fei Ding Xiao-Ou Jin State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Materials and Chemistry School Zhongyuan University of Technology National Center for Materials Service Safety University of Science and Technology Beijing School of Architecture and Engineering Heilongjiang University

intermetallic Ti-xAl-8Nb（x = 41,43,45,47,49;at%） alloys were solidified unidirectionally upwards with a constant temperature gradient of G=3.8 K·mm^（-1）at wide range of growth rates of v=10-400 μm·s^（-1）using a Bridgman directional solidification（DS） furnace.Microstructural parameters including the primary dendrite arm spacing（λ_1）,secondary dendrite arm spacing（λ_2）,dendrite tip radius（R） and mushy zone depth（d） were measured statistically.The values of λ_1,λ_2,R and d decrease as the growth rate increases for a given composition（x）.The values of λ_1,λ_2,R and v increase with the increase in x value,while the value of d firstly increases and then decreases with the increase in x value for a given v.The relationships between λ_1,λ_2 and R were analyzed by the linear regression.The average growth rate exponent of λ_1 is 0.29,which is in accordance with the previous experimental observations,and that of λ_2 is close to the previous experimental results,while those of R and d are lower than the results in other alloy systems.In addition,theoretical models for λ_1,λ_2 and R were compared with the experimental observations,and a comparison of the present experimental results with the theoretical models and previous experimental results was also made.

关键词： TiAl-Nb alloys intermetallic Directionalsolidification Microstructural parameters Soluteconcentration

A novel method to fabricate TiAl intermetallic alloy 3D parts using additive manufacturing

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Defence Technology（防务技术） 2017年第2期13卷 72-76页

作者： J.J.S. Dilip H. Miyanaji Austin Lassell Thomas L. Starr Brent Stucker Rapid Prototyping Center Department of Industrial EngineeringUniversity of LouisvilleLouisvilleKY 40292USA Department of Chemical Engineering University of LouisvilleLouisvilleKY 40292USA 3DSIM 1794 Olympic ParkwaySuite 110Park CityUT 84098USA

The present work explores the feasibility of fabricating porous 3D parts in TiAl intermetallic alloy directly from Tie6Ale4V and Al powders. This approach uses a binder jetting additive manufacturing process followed by reactive sintering. The results demonstrate that the present approach is successful for realizing parts in TiAl intermetallic alloy.

关键词： Additive manufacturing Binder jetting intermetallic Titanium aluminide Reactive sintering