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Boosting Oxygen Evolution Reaction Performance on NiFe‑Based Catalysts Through d‑Orbital Hybridization

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Nano-Micro Letters 2025年第1期17卷 281-292页

作者： Xing Wang Wei Pi Sheng Hu Haifeng Bao Na Yao Wei Luo state key laboratory of New Textile materials and advanced Processing Technology Key Laboratory of New Textile Materials and Applications of Hubei ProvinceSchool of Materials Science and EngineeringWuhan Textile UniversityWuhan 430200People’s Republic of China College of Chemistry and Molecular Sciences Wuhan UniversityWuhan 430072People’s Republic of China

Anion-exchange membrane water electrolyzers(AEMWEs)for green hydrogen production have received intensive attention due to their feasibility of using earth-abundant NiFe-based *** introducing a third metal into NiFe-based catalysts to construct asymmetrical M-NiFe units,the d-orbital and electronic structures can be adjusted,which is an important strategy to achieve sufficient oxygen evolution reaction(OER)performance in ***,the ternary NiFeM(M:La,Mo)catalysts featured with distinct M-NiFe units and varying d-orbitals are reported in this *** and theoretical calculation results reveal that the doping of La leads to optimized hybridization between d orbital in NiFeM and 2p in oxygen,resulting in enhanced adsorption strength of oxygen intermediates,and reduced rate-determining step energy barrier,which is responsible for the enhanced OER *** critically,the obtained NiFeLa catalyst only requires 1.58 V to reach 1 A cm^(−2) in an anion exchange membrane electrolyzer and demonstrates excellent long-term stability of up to 600 h.

关键词： NiFe-based catalysts d-orbital coupling Oxygen evolution reaction Anion exchange membrane electrolyzer

Effects of simulated on-fire processing conditions on the microstructure and mechanical performance of Q345R steel

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International Journal of Minerals,Metallurgy and materials 2016年第1期23卷 49-56页

作者： Yi-chao Peng Hao-hao Xu Mai-cang Zhang Department of materials Technology Zhejiang Energy Technology & Research Co.Ltd. Department of materials Science and Engineering University of Science and Technology Beijing

A series of simulated on-fire processing experiments on Q345R steel plates was conducted, and the plates＇ Brinell hardness, ten- sile strength, and impact energy were tested. Microstructure morphologies were systematically analyzed using a scanning electron micro- scope with the aim of investigating the effect of the steel＇s microstructure on its performance. All examined performance parameters exhib- ited a substantial decrease in the cases of samples heat-treated at temperatures near 700℃. However, although the banded structure decreased with increasing treatment temperature and holding time, it had little effect on the performance decline in fact. Further analysis revealed that pearlite degeneration near 700℃, which was induced by the interaction of both subcritical annealing and conventional spherical annealing, was the primary reason for the degradation behavior. Consequently, some nonlinear mathematical models of different mechanical perform- ances were established to facilitate processing adjustments.

关键词： low alloy steels heat treatment mechanical properties microstructure nonlinear mathematical models

Microstructure evolution and coercivity mechanism of hydrogenation-disproportionation-desorption-recombination(HDDR) treated Nd-Fe-B strip cast alloys

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Journal of Rare Earths 2022年第5期40卷 792-799,I0005页

作者： Bin Ma Xiaoqian Bao Aizhi Sun Jiheng Li Xuexu Gao state key laboratory for advanced metals and materials University of Science and Technology BeijingBeijing 100083China Institute for advanced materials and Technology University of Science and Technology BeijingBeijing 100083China

In this paper,we systematically investigated the microstructure evolution and coercivity mechanism of hydrogenation-disproportionation-desorption-recombination(HDDR)treated Nd-Fe-B strip cast alloys by transmission electron microscopy(TEM)and three-dimensional atom probe(3 DAP)*** rodlike NdH_(2+x) phases with diameters of 10-20 nm are embedded intoα-Fe matrix,which hereditarily leads to textured grains in HDDR *** migration of NdH_(2+x) from Nd-rich region toα-Fe matrix during hydrogen absorption process contributes to the uniform redistribution of Nd-rich phases after HDDR treatment The HDDR alloy with single domain grain sizes of 200-300 nm exhibits relatively low coercivity of 1.01 T that arises from pinning magnetic domain *** weak c-axis orientation of HDDR alloy results in a lower reverse magnetic field(coercivity)to reduce remanence to ***,the direct contact of Nd_(2)Fe_(14)B grains and the high concentration of ferromagnetic elements(Fe content≈66.06 at%,Co content≈0.91 at%)in Nd-rich grain boundary layer lead to strong magnetostatic coupling effect among Nd_(2) Fe_(14)B *** nano-sized a-Fe inside Nd_(2) Fe_(14)B matrix makes the magnetization reversal easily and decreases the coercivity of HDDR alloy.

关键词： Nd-Fe-B strip Cast HDDR treatmemt Microstructure evolution Coercivity mechanism Three-dimensional atom probe Rare earths

Improvement of microstructure and coercivity for Nd-Fe-B sintered magnets by boundary introducing low melting point alloys

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Journal of Rare Earths 2020年第4期38卷 395-401页

作者： Shuai Cao Xiaoqian Bao Jiheng Li Haijun Yu Kunyuan Zhu Xuexu Gao state key laboratory for advanced metals and materials University of Science and Technology BeijingBeijing 100083China

Different from the grain boundary diffusion process(GBDP),which is suitable for modifying thin magnet,a green-pressing agents permeation process(GAPP)that uses low melting point alloys was applied to the Nd-Fe-B green compact with a thickness over 15 mm to reconstruct the boundary microstructure of a sintered Nd-Fe-B *** coercivity increases from 12.3 kOe for the sample free of Pr80Al20 to16.8 kOe for the sample with 2 wt%*** further increasing the Pr80Al20 content to 3 wt%,the coercivity increases slightly,but the remanence and Hk/Hcj deteriorate *** optimal comprehensive properties of Hcj=16.8 kOe,Br=13.4 kG and Hk/Hcj=0.975 are obtained at 2 wt%Pr80Al20,since matrix phase grains are separated by relatively continuous thin grain boundary layers,which weaken the magnetic coupling between adjacent *** coercivities of the samples from the GAPP that use2 wt%Pr80Al20,Pr70Al30 and Pr60Tb20Al20 alloys,respectively,can be enhanced to a large ***,the coercivity of the magnet reconstructed with Pr80Al20 is lower than that of the sample with Pr60Tb20Al20 but is higher than that of the sample reconstructed with Pr70Cu30 ***,the coercivity of the sample from the GAPP using 2 wt%Pr80Al20 is much higher than that of the sample from the GBDP,which is due to a nearly uniform boundary microstructure from the surface to the interior of the thick magnet from the GAPP,thus providing new insights into the fabrication of thick and bulky permanent magnets with high coercivity.

关键词： Nd-Fe-B sintered magnets Green-pressing agents permeation Grain boundary diffusion Pr-Al alloys Thick and bulky magnets Rare earths

Tailoring the mechanical anisotropy of sintered NdFeB magnets by Pr-Cu grain boundary reconstruction

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Journal of Rare Earths 2019年第4期37卷 393-397页

作者： Minghui Tang Xiaoqian Bao Xuejiao Zhang Xing Mu Kechao Lu Jiheng Li Xuexu Gao state key laboratory for advanced metals and materials University of Science and Technology Beijing School of Metallurgical and Ecological Engineering University of Science and Technology Beijing

Pr_(83)Cu_(17)(wt%) grain boundary reconstruction was applied to prepare sintered NdFeB magnets. The effects of addition amount and annealing on the bending strength were investigated. The results show that Pr_(83)Cu_(17) can not only effectively enhance the bending strength, but also change the mechanical anisotropy in two directions parallel and perpendicular to c-axis. The bending strength perpendicular to c-axis reaches 404 MPa in 10 wt% addition magnet, higher than 348 MPa along parallel direction. This change is attributed to the preferred distribution of boundary phases, i.e., ductile(Nd,Pr)-Fe-Cu phase along perpendicular direction to c-axis and(Nd,Pr)-Fe phase along parallel direction. Moreover, the Cu migration during 480 ℃ annealing is found to be related to this boundary phase distribution.

关键词： Mechanical properties Sintered Nd-Fe-B magnet Pr-Cu alloy Rare earths

Effect of molybdenum content on the microstructure and corrosion behavior of FeCoCrNiMox high-entropy alloys

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Journal of materials Science & Technology 2020年第11期42卷 64-73页

作者： Chunduo Dai Tianliang Zhao Cuiwei Du Zhiyong Liu Dawei Zhang Institute for advanced materials and Technology University of Science and Technology BeijingBeijing 100083China key laboratory for Corrosion and Protection of The Ministry of Education(MOE) Beijing 100083China Beijing advanced Innovation Center for materials Genome Engineering University of Science and Technology BeijingBeijing 100083China materials Genome Institute of Shanghai University Shanghai 200444China

The effect of Mo content on the microstructure revolution and corrosion behavior of cast FeCoCrNiMox high-entropy alloys in chloride environments were *** indicate that FeCoCrNi and FeCoCrNiMo0.1 alloys are in single FCC solid *** precipitates form in FeCoCrNiMo0.3 and increase in FeCoCrNiMo0.6 *** occurs on FeCoCrNi and FeCoCrNiMo0.1 alloys while FeCoCrNiMo0.3 and FeCoCrNiMo0.6 alloys suffer from preferential localized corrosion at the regions depleted in Cr and *** higher Cr2O3/Cr(OH)3 ratio and the incorporation of Mo oxides make the passive film more protective and the corrosion resistance of the FeCoCrNiMo0.1 alloy is thus *** correlation between microstructure and corrosion behavior and the corresponding corrosion mechanism were clarified.

关键词： High-entropy alloys Corrosion behavior Precipitate

Differences in the structure and magnetic properties of(Nd0.75Pr0.25)9.5Fe76X4B10.5(X=Nb, Zr) ribbons by conventional and microwave-assisted annealing treatment

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Journal of Rare Earths 2017年第7期35卷 667-672页

作者：王天鹏王占勇杨文亚周鼎吴佳恒周冰金鸣林董广乐隋延力 School of materials Science and Engineering Shanghai Institute of Technology Shanghai 201418 China state key laboratory for advanced metals and materials University of Science and Technology Beijing Beijing 100083 China

Amorphous ribbons with（Nd_（0.75）Pr_（0.25））_（9.5）Fe_（76）X_4B_（10.5）（X=Nb, Zr） nominal composition were annealed by conventional and microwave-assisted annealing furnaces, respectively. The thermal decomposition process, structure and magnetic properties of products were characterized by a thermal differential scanning calorimeter（DSC）, X-ray diffraction（XRD） and a vibrating sample magnetometer（VSM）. The addition of Nb and Zr increased the glass-forming ability（GFA） of as-spun ribbons. The proportion of Nd_2Fe_（14）B and α-Fe could be adjusted with power from 800 to 2000 W in microwave annealing process, during which the well-coupling between the soft and hard magnetic phase and higher coercivity reached up to 780.2 and 815.4 kA/m for（Nb,Zr）-doped alloys. The best magnetic properties of ribbons could be obtained by annealing at 650 oC for 10 min under the microwave power of 2000 W.

关键词： magnetic properties α-Fe/Nd2Fe14B crystallization kinetics microwave-assisted annealing rare earths

Gelcasting of titanium hydride to fabricate low-cost titanium

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Rare metals 2015年第5期34卷 351-356页

作者： Qing Ye Zhi-Meng Guo Jian-Ling Bai Bo-Xin Lu Jun-Pin Lin Jun-Jie Hao Ji Luo Hui-Ping Shao Institute for advanced materials and Technology University of Science and Technology Beijing state key laboratory of advanced metals and materials University of Science and Technology Beijing

In this work, low-cost titanium was fabricated by gelcasting of titanium hydride powder. The effects of morphology and grain composition of powder raw material and solid loading on the rheological behavior of gelcasting slurry were studied. The degreasing, dehydriding and sintering behaviors of gelcasted green body were investigated by differential thermal analysis （DTA） and dilatometer. The results show that the solid loading of titanium hydride slurry reaches 50 vol%. Combination of dehydriding and sintering in one process accelerates the densification, and the relative sintered density of the final part achieves 96.5 %. In order to test the ability of gelcasting process for fabricating structural materials, a resin handle produced by 3D printing technology was used as a model and a titanium handle was successfully fabricated. Higher solid loading and better sinterability of titanium hydride powder promote manufacture of bulk titanium with high relative density, complex shape and well-defined microstructure.

关键词： Gelcasting Titanium hydride Powder metallurgy Sintering Titanium

Warm deformation behavior and work-softening mechanism of Fe- 6.5wt.%Si alloy

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Journal of Iron and Steel Research International 2020年第3期27卷 342-354页

作者： Xiang-ju Shi Yong-feng Liang Bin-bin Liu Bao Zhang Feng Ye state key laboratory for advanced metals and materials University of Science and Technology BeijingBeijing 100083China

Warm deformation behavior of the Fe-6.5wt.%Si alloy was studied by isothermal compression in the temperature range of 300-700℃.The results show that the influence of the ordered phases on the flow stress gradually weakens with increasing deformation *** flow stress of the furnace-cooled sample with the high degree of order at 300℃is higher than that of the quenched sample with the low degree of order,and the flow stresses of both samples are nearly the same at 500-700℃.The hardness difference between two samples deformed at 500℃gradually decreases with increasing strain,accompanying with a reduction in hardness of the furnace-cooled sample,which indicates a work-softening *** analyses of dislocation configurations and ordered structure suggest that the dynamic recovery and deformation-induced disorder result in the work-softening *** appropriate deformation temperature window for improving the formability of the Fe-6.5wt.%Si alloy is about 500-600℃.

关键词： Fe-6.5wt.%Si alloy Work softening Ordered structure Dynamic recovery Anti-phase boundary Dislocation