JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
·
2024
·
IF 2.2
Li Pengfei,Sui Yudong,Jiang Yehua,Zhou Mojin,Wang Zhijie
The effects of MgO addition on the microstructure and mechanical, frictional, and wear properties of zirconia-toughened alumina (ZTA) ceramics were investigated in this study using hot pressure sintering (HP). The addition of trace amounts of MgO led to the refinement of the ceramic grains and an increase in the ceramic density due to the pinning effect of MgO. X-ray diffraction (XRD) and scanning electron microscopy (SEM) results revealed that an MgAl 2 O 4 phase was formed in the ceramics, which also contributed to the refinement of the ceramic grains. Moreover, the addition of MgO promoted the uniformity of the ceramic microstructure. Among the tested composites, the composite with 0.4 wt.% MgO exhibited the most favorable comprehensive properties, including a relative density of 99.61%, hardness of 18.29 GPa, and indentation fracture toughness of 9.15 MPa·m 1/2 , thereby offering the highest resistance to adhesive wear.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Jian Li,Xiaohan Zhang,Jia Liu,Qingxuan Zhou,Haitao Wu,Yuanyuan Zhou,Yang Wang,Wei Sun,Yanxiang Jiang,Yongning Han,Zhuoqun Han,Zhicheng Zhao,Futian Liu,Walther Glaubitt,Yongcui Zhang,Yingying Wang,Ling Li
(1- x )MgAl 2 O 4 - x MgTa 2 O 6 composite ceramics based on the MgO-Al 2 O 3 -Ta 2 O 5 pseudoternary phase diagram were prepared by the solid-state reaction. MgAl 2 O 4 and MgTa 2 O 6 could coexist due to their different crystal structures. MgAl 2 O 4 inhibited the rapid growth of MgTa 2 O 6 grains, and dense microstructures ( ρ > 95%) with a uniform grain size distribution was obtained, with an optimal densification temperature of 1550 - 1575 °C. The temperature coefficient of resonant frequency ( τ f ) and quality factor ( Q × f ) were optimized by introducing MgTa 2 O 6 phases with low dielectric loss and positive τ f . In addition, the partial solid solutions of Al 3+ into Ta 5+ sites resulted in loosening bonds within [Al/TaO 6 ] octahedra and abnormally large polarizabilities, which was confirmed by the decrease in V Ta-O and the redshift of A 1 g (Ta-O) mode. Consequently, the relative permittivity ( ε r ) and τ f values o f MgAl 2 O 4 -MgTa 2 O 6 composite ceramics were further enhanced, exceeding the predicted ones. The 0.6MgAl 2 O 4 -0.4MgTa 2 O 6 composition sintered at 1550 °C achieved excellent performance, with a near-zero τ f value of 3.3 ± 1.7 ppm/°C, a low ε r of 16.4 ± 0.3 and an ultra-high Q × f of 179,000 ± 6700 GHz @ 8.94 ± 0.04 GHz. These findings hold promising applications in the field of 5 G/6 G high-frequency communication.
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2024
·
IF 5.2
Tianxu Su,Bin Guan,Chunzheng Zheng,Jiefei Zhou,Zhen Huang
Developing low-temperature, high-efficiency ammonia decomposition catalysts for hydrogen production is essential for the broad application of hydrogen. This study conducted a systematic investigation of Ru/MgO catalysts modified with different alkali metals (Na, K, Cs), unveiling the impact of these modifications on catalyst performance and developing a highly efficient low-temperature ammonia decomposition catalyst. The addition of all alkali metals enhances the catalytic performance of Ru/MgO for ammonia decomposition, especially the addition of K, which results in the optimal enhancement of the catalyst, achieving a 75% ammonia decomposition efficiency at 350 °C (GHSV= 2,000 mL/h·gcat), more than doubling the performance of the unmodified Ru/MgO catalyst. The study revealed that the addition of potassium (K) altered the rate-determining step of the ammonia decomposition reaction from nitrogen recombination to the dissociation of the first hydrogen atom, and reduced the overall energy barrier required for the reaction. This facilitated the desorption of nitrogen from the Ru surface and the conversion of NH3, thereby accelerating the rate of the ammonia decomposition reaction.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2024
·Vol. 59
·期 36
·16909-16917
·
IF 3.5
Xie Jingru,Fu Zhifen,Cheng Qing,Chen Chen,She Yubin,Li Xiangyi
Low temperature co-fired ceramics (LTCC) technology is extensively utilized to meet the requirements of device integration and miniaturization. Low-fired Li 3 Mg 2 NbO 6 ceramics doped with x wt% Li 2 O–MgO–B 2 O 3 –CaF 2 –SiO 2 glass (LMBCS, x = 0.5, 1.0, 1.5, 2.0) were prepared by the solid-state reaction method for applications in microwave communication materials. All samples exhibited a single-phase Li 3 Mg 2 NbO 6 structure. The addition of LMBCS glass effectively reduced the sintering temperature of Li 3 Mg 2 NbO 6 ceramics from 1250 °C to 875 °C. And adding LMBCS glass improved the Q × f value of Li 3 Mg 2 NbO 6 ceramics. The Li 3 Mg 2 NbO 6 -1.0wt% LMBCS ceramics exhibited outstanding microwave dielectric properties: ε r = 16.8, Q × f = 89,495 GHz, τ f = − 27.4 ppm/°C at 875 °C, which indicates that this ceramic is potential candidate materials for LTCC.
研究领域:
材料科学
·
电子陶瓷
·
功能材料
·
无机非金属材料
·
微波通信材料
✓ 已验证
DOI
高影响因子
Journal of the Australian Ceramic Society
·
2025
·
IF 2.1
Qian Kaichen,Fan Jintai,Shen Zongyun,Li Kai,Zhou Weiwen,Feng Minghui,Jiang Benxue,Zhang Long
The influence of Gd 2 O 3 phase on microstructure, optical, mechanical and thermal properties in Gd 2 O 3 -MgO nanocomposite ceramics was investigated. A self-propagating high-temperature synthesis (SHS) method was adopted to synthesize Gd 2 O 3 -MgO nanopowders. The pressureless sintering and hot isostatic pressing (HIP) technique were applied to obtain IR-transparent composite ceramics. The Gd 2 O 3 can be stabilized as the cubic structure with 10 at% Y-doping in Gd 2 O 3 -MgO nanocomposite ceramics (named GYM). Optical and mechanical properties of the GYM were compared with the Gd 2 O 3 -MgO without Y-doping samples (named GM) in which Gd 2 O 3 was monoclinic. The flexural strength, emittance of Gd 2 O 3 -MgO nanocomposite ceramics at high temperature were measured for the first time as far as we know. The comparison demonstrated that the GM exhibiting a more promising potential application performance for MWIR windows, with an in-line transmittance of 79.2–83.3% at 3–5 μm, Vickers hardness of 9.6 GPa, flexural strength of 508 MPa, emissivity of 0.02 at 4 μm (800 ℃) and the Hasselman mild-thermal-shock figure of merit R’ =2.0.
研究领域:
材料科学
·
陶瓷
·
红外光学
·
纳米复合材料
·
热学与力学性能
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Ziheng Han,Tuo Guo,Yuhai Liu,Yuzhe Lu,Jingjing Ma,Xiude Hu,Qingjie Guo
The limited reactivity of single transition metal nitrogen carrier (NC) is a significant factor contributing to the suboptimal performance of chemical looping ammonia production (CLAP). This research proposes a strategy of loading alkaline earth metal oxides to construct a vanadium-based NC loading CaO (VN/CaO composite NC) with enhanced reactivity. The results demonstrate that the incorporation of CaO increases the lattice nitrogen conversion rate of VN from 4 % to 21 % and reduces the ammonia production temperature. The ammonia production rate of VN/CaO composite NC reaches 481.25 μmol·g −1 ·h −1 at 800 °C. In contrast, the electron-donating ability of MgO is weaker than that of CaO, and the ammonia production rate of the VN/MgO is 350 μmol·g −1 ·h −1 . Theoretical calculations and experimental characterizations reveal that CaO maintains the surface basicity of the NC, creating an electron-rich surface that weakens the V N bond strength, promotes H 2 adsorption and dissociation, and enhances the reactivity of vanadium-based NC. The reaction mechanism of VN/CaO composite NC follows the Mars-van Krevelen mechanism, with the hydrogenation of NH 3 intermediates identified as the rate-determining step. This study provides theoretical support for the development of multi-component composite NC.
研究领域:
化学工程
·
催化
·
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2022
·Vol. 105
·期 11
·6953-6964
·
IF 4.186
Yuchao Qiu,Junjie Shi,Bin Yu,Changle Hou,Jingjing Dong,Song Li,Yumo Zhai,Jianzhong Li,Changsheng Liu
The recycling of titanium from titania-bearing slag is an important part of the circular economy; however, the yield of titania is restricted due to the lack of fundamental thermodynamic data. In the present work, the equilibrium phase relations of MgO–Al 2 O 3 –TiO 2 system in air at 1600°C have been determined using a high-temperature equilibration-quenching technique followed by X-ray photoelectron spectroscopy, scanning electron microscopy-energy-dispersive X-ray spectrometry, and X-ray diffraction. Ti 4+ was confirmed as the stable valence of titanium, and the rutile and spinel solid solution phases were detected to be coexisting with pseudobrookite solid solution phase, respectively. The formation principles of pseudobrookite and spinel solid solutions were confirmed in view of the corresponding crystal structure and the composition substitution relationship of the oxides at 1600°C. However, great discrepancies were found from the comparison of the present experimental results with the thermodynamic calculations and the literature results, and the present equilibrium phase relations are therefore significant for updating the present titania related thermodynamic database for a superior prediction of the thermodynamic behaviors of relevant process.
研究领域:
材料科学
·
冶金工程
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2026
·
IF 6.3
Quanhui Hou,Qianyang Wang,Xiao Xu,Zhihao Xu,Peng Jiang,Maziar Ashuri,Yunxuan Zhou,Zhao Ding
Developing efficient and scalable catalysts remains crucial for advancing practical MgH 2 -based solid-state hydrogen storage. In this work, an oxide-precatalyst strategy is proposed, where Fe 3 O 4 nanoparticles are uniformly anchored on leaf-derived porous carbon to form a Fe 3 O 4 /leaf-carbon catalyst that converts in situ into highly dispersed Fe/MgO interfaces during the initial dehydrogenation process. The resultant MgH 2 + 10 wt% Fe 3 O 4 /leaf-carbon composite exhibits a markedly improved hydrogen sorption performance, with an onset desorption temperature of 215 °C, releasing 6.41 wt% H 2 within 8 min at 350 °C, and reabsorbing 6.22 wt% H 2 at 175 °C (3 MPa) within 1 h. Notably, the activation energies for hydrogenation and dehydrogenation are drastically reduced to 53.27 kJ mol −1 and 91.45 kJ mol −1 , respectively. Furthermore, after undergoing 20 consecutive adsorption cycles, this composite material still maintained 96.3 % of its hydrogen storage capacity compared to the initial hydrogen absorption. Structural characterizations confirm that Fe 3 O 4 is reduced to Fe while forming a stable Fe/MgO heterointerface that provides abundant active sites and accelerates hydrogen diffusion. This study elucidates the oxide-to-metal interface transformation mechanism as an effective pathway to simultaneously lower thermodynamic barriers and enhance kinetic reversibility, offering a cost-effective and sustainable strategy for engineering next-generation MgH 2 -based hydrogen storage materials.
✓ 已验证
产品关联
DOI
高影响因子
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
·
2026
·
IF 3.1
An Zhuoqing,Liang Weiwen,Gao Yuan,Chen Jiajing
The viscosity of the CaO–MgO–Al 2 O 3 –SiO 2 system containing La 2 O 3 and Fe 2 O 3 was measured by rotation, hot-stage microscopy and hot-stage load methods to investigate the rheological behavior across multiple temperature ranges. In-situ high temperature Raman spectroscopy was employed to quantitatively analyze the microstructure. The results show that with the La 2 O 3 /Fe 2 O 3 ratio varying from 2/0 to 0/2, the viscosity decreases gradually through the multiple temperature ranges, and the viscous flow activation energy also gradually decreases. As the ratio of La 2 O 3 /Fe 2 O 3 decreases, the relative contents of Q 0 , Q 1 and Q 2 increase gradually, and the relative contents of Q 3 and Q 4 decrease significantly. This indicates that both La 2 O 3 and Fe 2 O 3 act as network modifiers and simplify the glass network structure, resulting in a decrease in the degree of network polymerization and viscosity over the multiple temperature range. Compared to La 2 O 3 , Fe 2 O 3 is a more effective network modifier, as it breaks up the silicate network more efficiently and results in a lower overall viscosity. In addition, the microstructure of the melts was quantitatively analyzed by NBO/ T , and a quantified relationship among viscosity, microstructure and temperature was given.
✓ 已验证
产品关联
DOI
高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2023
·
IF 4.5
Miao TIAN,Qiong-qiong WANG,Qin-meng WANG,Wei LI,Xue-yi GUO
The effect of MgO on the phase equilibria between matte and tridymite-saturated FeO x −SiO 2 −MgO slag was investigatedusing high-temperature equilibration and microanalysis technique. The results showed that at 1300 °C and p (SO 2 ) of 10 kPa, the presence of MgO reduced the FeO activity of the slag, leading to the decrease in the oxygen partial pressure ( p (O 2 )) over the slag and the Cu solubility in the slag. Due to the lower FeO activity, FeS was oxidized from matte into slag, increasing the Cu concentration of the matte. In high-SiO 2 concentrationslags, excessive MgO in the liquid slag recrystallized as solid olivine (Mg 2 SiO 4 −Fe 2 SiO 4 ), increasing the slag viscosity and copper losses in the slag. The maximum MgO solubility in the FeO x −SiO 2 −MgO slag increased from 3 wt.% to 8 wt.% when the temperature raised from 1200 to 1300 °C under p (O 2 ) of 10 −6 kPa. At higher MgO content, the slag composition could be optimized by increasing temperature and adding SiO 2 flux to maintain a fully molten slag or avoid high proportions of solids.
研究领域:
冶金学
·
材料科学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2026
·
IF 9.1
Peizhen Zhang,Chenxi Li,Lili Huo,Lixin Zhao,Zonglu Yao
To enhance the application potential of straw-based biochar in CO 2 capture, this study prepared nano-MgO-supported biochar (MgO/BMBC) via a combined ball-milling and MgO-modified pyrolysis activation process. The CO 2 adsorption performance of the material was systematically investigated, and the adsorption mechanism was elucidated through structure-property relationship analysis and density functional theory (DFT) calculations. The results indicate that wet-milled biochar (W-MgO@BMBC) exhibits a hierarchical pore structure and a specific surface area of 323.14 m 2 ·g −1 . This method promotes the formation of a hierarchical porous structure, the presence of oxygen-containing basic groups, and the loading of MgO. The maximum CO 2 capture capacity reached 1.29 mol·kg −1 under conditions of 273 K and 1 bar, with the mechanism of action being a synergistic effect of physical and chemical adsorption. The CO 2 /N 2 selectivity is 40.28, and after five cycles, the adsorption capacity loss is significant at approximately 40%, necessitating further improvement. DFT calculations indicate that enhancing the affinity between MgO/BMBC and CO 2 and facilitating electron transfer reduces the adsorption energy, thereby improving CO 2 capture performance. This study provides a new strategy for the preparation of highly efficient, low-cost solid CO 2 adsorbents.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2026
·Vol. 40
·期 5
·e70581
·
IF 4.3
Wenjing Song,Zhenhao Xiao,Shuo Yan,Jie Li,Weizuo Li,Haiqun Chen
The chemical fixation of carbon dioxide (CO 2 ) into value-added cyclic carbonates is a promising pathway for carbon utilization; however, developing heterogeneous catalysts with high activity and stability remains a challenge. In this study, a Cu–Mg-MOF-74 precursor was synthesized via a solvothermal method and subsequently transformed into a Cu–Cu 2 O–MgO/C nanocomposite catalyst through a one-step pyrolysis process under N 2 atmosphere at 550°C. The pyrolysis process leads to the collapse of the MOF crystal structure and the formation of highly dispersed Cu–Cu 2 O–MgO nanoparticles embedded in a carbon matrix, while the overall morphology inherited from the MOF precursor remains largely preserved. Detailed characterization (XRD, XPS, TEM, BET, and in situ DRIFTS) reveals that the catalyst possesses a high specific surface area (296.7 m 2 ·g −1 ), abundant Lewis acid sites (Cu, Cu 2 O, and MgO), and surface oxygen-containing groups, which synergistically enhance catalytic performance. Under relatively moderate conditions (90°C, 0.7 MPa, CO 2 , 7 h), the Cu–Cu 2 O–MgO/C catalyst achieved a styrene oxide conversion of 94% with 99% selectivity, significantly outperforming its monometallic and physical mixture counterparts. Furthermore, the catalyst demonstrated excellent substrate versatility and robust recyclability over five consecutive runs without structural collapse. This work provides a facile strategy for fabricating robust MOF-derived carbon-based catalysts for sustainable CO 2 conversion.
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）