CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Zijun Peng,Lei Yuan,Xudong Luo,Jingkun Yu,Chen Tian,Zhenli Liu
MgO–Al 2 O 3 –SiO 2 composite ceramics were prepared by spark plasma sintering (SPS). In addition, phase composition, microstructure, mechanical properties , and thermal shock properties have been systematically characterized. Introduction of Al 2 O 3 and SiO 2 significantly increased mechanical properties and thermal shock resistance of these composite ceramics. MgO–Al 2 O 3 –SiO 2 composite ceramics prepared by spark plasma sintering (SPS) exhibited fine grain size. Reduced grain size may result in extraordinary properties. Experimental results showed that MgO–Al 2 O 3 –SiO 2 composite ceramics had the highest flexural strength and hardness among all studied ceramics of 269.6 ± 9.22 MPa and 12.51 ± 0.29 GPa, respectively. Moreover, MgO–Al 2 O 3 –SiO 2 composites can reach 16 thermal cycle times. This shows that it is feasible to prepare high-performance MgO composite ceramics by SPS. Furthermore, introduction of Al 2 O 3 and SiO 2 is effective method to improve mechanical properties and thermal shock resistance of MgO composite ceramics.
研究领域:
材料科学
·
陶瓷工程
·
先进制造
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Xiaoqian Feng,Yilin Zhao,Shenghua Liu,Kun Wang,Baoshan Liu,Qijian Zhang,Huan Wang,Yonghua Zhao,Jing Liu,Peng Zhang,Lian Gao
Dry reforming of methane (DRM) suffers catalysts deactivation due to severe coking. Ni/MgO-Al 2 O 3 is a promising system for DRM catalysts with high coking resistance, as the addition of MgO in Ni/Al 2 O 3 catalysts can improve the alkalinity of the support and enhance the metal-support interaction. However, so far the activity and stability of Ni/MgO-Al 2 O 3 is still unsatisfactory while the role of Mg addition remains unclear. In this paper, a series Ni 0.5 /xMgO-Al 2 O 3 catalysts with flower-like hollow sphere morphology and high surface area were synthesized via a facile hydrothermal method. Appropriate Mg addition promotes the formation of NiAl 2 O 4 while more Mg addition leads to the formation of Ni x Mg y O. Both cases can enhance the MSI of the catalysts without changing the morphology of the catalyst. More Mg addition also leads to stronger CO 2 adsorption via improving the alkalinity. Nevertheless, overdose of Mg results in weaker MSI and the blockage of Ni active sites. Ni 0.5 /0.5MgO-Al 2 O 3 with moderate Mg addition shows excellent activity (CH 4 ∼ 75 %, CO 2 ∼ 85 %) and stability (>100 h) at a high GHSV = 144000 ml/g cat ·h −1 and 800 °C with nearly no coking formation (<0.8 wt%). This work helps reveal the role of MgO addition in Ni/Al 2 O 3 systems and gives new insights into the design of DRM catalysts with high activity and stability.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2025
·
IF 3.9
Rui Xing,Yanan Jiang,Jia Li,Pengxiang Liu,Yuan Liu,Cuijuan Zhang
Despite significant advances in catalytic activity for CO2 methanation, the catalyst stability has received less attention, limiting its application. This work prepared Ni-supported on MgO-Al2O3 with varying Mg/Al ratio (x) and studied their deactivation mechanism. The deactivation was accelerated by a stability test at 600 °C for 200 h. The activity comparison before and after the stability test reveals that the sample with x = 0.4 shows the best stability without obvious activity decline. While the sample with x = 0.3 is deactivated due to Ni sintering, samples with x = 0.5 and 0.6 are deactivated by the oxidation of Ni, which easily forms a solid solution with excess MgO but is difficult to reduce. That assertion is supported by various characterizations. Such an oxidative deactivation is first-time reported for Ni-based catalysts for CO2 methanation, which could shed light on their rational design and industrial application.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2025
·
IF 6.2
Yuxiang Shen,Huan Liu,Raz Muhammad,Yang Yao,Xueqing Yu,Alexander Korotkevich,Minmin Mao,Lei Cao,Bing Liu,Haishen Ren,Huixing Lin,Matjaz Spreitzer,Mikhail P. Kuz'min,Ruzhong Zuo,Kaixin Song
In this study, 21.9 mol% MgO - 20.3 mol% Al 2 O 3 - 54.6 mol% SiO 2 + 1.6 mol% MnO 2 + 1.6 mol% ZnO and 23.1 mol% MgO - 20.9 mol% Al 2 O 3 - 55.0 mol% SiO 2 + 1.0 mol%GeO 2 were prepared by low-temperature co-firing method. The effects of nucleating agents and sintering temperature on the crystallization behavior, microstructure and microwave dielectric properties of MASMZ and MASG glass-ceramics were investigated. It was found that both glass-ceramics were able to precipitate stable α-cordierite crystalline phases at relatively low temperatures. Crystallization kinetics analysis showed that MASMZ glass-ceramics crystallized more easily than MASG glass-ceramics. MASMZ glass-ceramics exhibited optimal dielectric properties at 925 °C: ε r = 4.74, tan δ = 8.1 × 10 −4 , τ f = -14 ppm/°C. MASG glass ceramics achieved optimal dielectric properties at 950 °C: ε r = 4.46, tan δ = 1.11 × 10 −3 , τ f = -27 ppm/°C. Especially, the excellent chemical stability and compatibility of MASMZ and MASG glass-ceramics with silver at high temperatures were verified, indicating the potential of MASMZ and MASG glass ceramics as LTCC substrate materials.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2021
·Vol. 36
·期 2
·174-182
·
IF 0.957
Shi Minxian,Tang Qingxiu,Fan Shanshan,Dong Chuang,Huang Zhixiong
The ceramifiable polymer composite of MgO-Al 2 O 3 -SiO 2 /boron phenolic resin(MAS/BPF) with 40wt% of inorganic fillers was calcined at 1 200 °C for different time to promote ceramification of ceramifiable composite and improve heat resistance. The effects of different calcine time on the macroscopical morphology, mass loss, phase evolution, microstructure and chemical bond evolution of MAS/BPF composites were characterized by XRD, XPS, and SEM analyses. The experimental results reveal that the increase of calcine time result in the fewer holes, relatively denser and smoother top layer of MAS/BPF composites and protect the interior from deeper decomposition. The final residues of composites are amorphous carbon and C-O-Si-Al-Mg ceramic. And MAS/BPF composites show excellent mass stability, low shrinkage and self-supporting features after 2 h holding compared with BPF composites without 40wt% of inorganic fillers.
研究领域:
材料科学
·
无机化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Yuzhu Su,Junpu Wang,Xin Li,Qiqi Tang,Jing Yang,Li Lei,Yi Tian,Zhiwei Wang,Duanwei He
The in situ axial X-ray diffraction patterns of four ceramic powder samples (MgO, Al 2 O 3 , AlN , and cBN) that were compressed in a diamond anvil cell under uniaxial non-hydrostatic conditions were recorded. The microscopic deviatoric stress as a function of the pressure was determined from the X-ray diffraction peak broadening analysis: the curves increased approximately linearly with the pressure at the initial compression stage and then levelled off under further compression. Pressure-induced transparency was observed in all of the samples under compression, and the pressure at the turning point on the curves of the microscopic deviatoric stress versus pressure corresponded to the pressure at which the samples became transparent. Analysis of the microstructural features of the pressure-induced transparent samples indicated that the compression caused the grains to fracture, and the broken grains bonded with each other. We demonstrated that the ceramics’ pressure-induced transparency was a process during which the grains were squeezed and broken, the pores were close between the grains, and the broken grains were re-bonded under compression.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
Processes
·
2022
·Vol. 10
·期 7
·1302
·
IF 3.352
Hailun Ren,Weihong Li
3-hydroxybutyraldehyde (3-HBA) is mainly employed to synthesize 1,3-BDO (1,3-butanediol), which is one of the most important components in cosmetics moisturizers. In this study, a series of composite oxide catalysts were prepared by bringing alkaline earth metal Ca and rare earth metal La to the composite oxide MgO/Al2O3, which were made through the co-precipitation method. These catalysts were applied in the synthesis of 3-HBA through acetaldehyde (AcH) condensation. The structure, texture, and acidic properties of these catalysts were characterized using various characterization methods, and the effects of catalyst composition, reaction temperature, reaction pressure, and residence time on the conversion of AcH were investigated as well. The results showed that the introduction of Ca and La weakened the acidic property and enhanced the basic property, which favored the AcH condensation to synthesize 3-HBA. At a temperature of 20 °C, pressure of 200 kPa, and residence time of 70 min, 0.5%La-2.3%Ca-2MgO/Al2O3exhibited a better catalytic activity, and the conversion of AcH reached 95.89%. The selectivity and yield of 3-HBA were 92.08% and 88.30%, respectively. The stability test indicated that the high AcH conversion could be maintained for 5 h.Keywords:composite oxides;acetaldehyde;condensation catalyst;3-hydroxybutyraldehyde
研究领域:
催化化学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Jiefu Lang,Ke Ren,Yiguang Wang
As a thermal barrier coating (TBC) material, 8 wt% yttria-stabilized zirconia (8YSZ) exhibits poor resistance against calcium–magnesium–aluminosilicate (CMAS) corrosion. This is caused by the penetration of molten CMAS glass and the depletion of Y 3+ , which limits the lifetime of 8YSZ. In this study, a multi-rare-earth-oxide-doped zirconia (15 wt% (Lu 0.2 Yb 0.2 Dy 0.2 Gd 0.2 Y 0.2 )–ZrO 2 , denoted as 15LYDGY–SZ) ceramic was prepared to examine its interaction with CMAS. The sluggish diffusion effect and the competition between various dopant elements toward reaction with CMAS effectively slow down the atomic diffusion and limit the transformation of tetragonal phase into monoclinic phase in 15LYDGY–SZ ceramic. Compared with the currently used 8YSZ ceramic, the corrosion resistance of 15LYDGY–SZ to CMAS and its retention rate of fracture toughness after CMAS corrosion are improved. The results show that the multi-rare-earth-oxide-doped zirconia ceramic prepared in this study is a promising candidate material for the development of future TBCs.
研究领域:
材料科学
·
航空工程
✓ 已验证
产品关联
DOI
高影响因子
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
·
2025
·
IF 3.1
Wang Jingzhi,Fan Shenghong,Li Xin,Wang Hongyang,Han Peiwei,Ye Shufeng
With the rapid advancement of short-process steelmaking technology and the demand for low-carbon emissions, electric arc furnace (EAF) has increasingly become a critical pathway in global steel production. This study systematically investigates the structure–property relationships and compositional regulation mechanisms of CaO–SiO 2 –FeO–MgO–Al 2 O 3 slag, focusing on the effects of high FeO content between 21 and 30 wt pct on viscosity, density, and microstructure. The viscosity and density of the homogeneous slags in the range between 1773 K and 1873 K were measured using the rotating cylinder and Archimedes methods, respectively. The short-range structural characteristics of slag systems with different FeO contents were analyzed by molecular dynamics simulations. The results indicate that as the FeO content increases, the liquidus temperature, viscosity, viscous flow activation energy, and the molar volume decrease accordingly, while the density increases. FeO promotes depolymerization of the aluminosilicate network, leading to an increase in the proportion of non-bridging oxygen and free oxygen and a decrease in bridging oxygen content. The results obtain the correlations between FeO content, network depolymerization, and changes in flow properties, providing a theoretical basis for slag composition optimization and foaming slag control in EAF operations.
研究领域:
冶金学
·
材料科学
·
炉渣化学
·
过程冶金
·
高温材料
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2017
·
IF 0
Hao Chen,Houhang Ruan,Xilei Lu,Jie Fu,Timothy Langrish,Xiuyang Lu
Catalytic transfer hydrogenation of furfural to furfuryl alcohol is considered to be a very important industrial process. In this work, non-noble Cu supported on MgO-Al 2 O 3 catalysts have been prepared by co-precipitation and have shown excellent catalytic performance for conversion of furfural to furfuryl alcohol in near-critical iso-propanol. The effects of the Cu state (reduction degree and dispersion) and loading in Cu/MgO-Al 2 O 3 , acidity of catalysts have been investigated by X-ray diffraction (XRD), coupled plasma optical emission spectrometry (ICP-OES), N 2 adsorption and desorption (N 2 -BET) and temperature-programmed desorption of ammonia (NH 3 -TPD), which have led to high activity for producing furfuryl alcohol. The results have shown that the selectivity of furfuryl alcohol has been influenced by the Cu state, Lewis acidity, reaction temperature and reaction time. The mechanisms, Lewis acid- and metal mediated hydrogenation, have shown that a desirable balance of Cu loading and Lewis acidity of catalyst has influenced the activity significantly. Almost 100% furfural conversion, with 89.3% furfuryl alcohol yield has been obtained. Cycling tests have shown that the prepared catalysts have been stable, where recycling the catalysts at least four times has not shown any reduction in activity.
研究领域:
化学工程
·
催化材料
✓ 已验证
DOI
CERAMICS INTERNATIONAL
·
2026
·
IF 6
Leibo Deng,Tianyi Li,Yahui Zhou,Wenjing Zhang
The harmless treatment of Cr-containing solid waste remains a critical environmental challenge. Herein, Cr 2 O 3 -doped CaO–MgO–Al 2 O 3 –SiO 2 glass-ceramics with varying Na 2 O contents were prepared via a melting method. The study focuses on how Na 2 O regulates the glass network, crystallization behavior, and Cr immobilization efficiency. With increasing Na 2 O content, the degree of depolymerization (DOD) of the parent glass increases from 1.76 to 1.99, while the crystallization activation energy decreases accordingly. The optimal formulation is achieved at 1 wt% Na 2 O combined with a two-stage heat treatment (nucleation at 720 °C for 2 h, followed by crystallization at 850 °C for 2 h). Under these conditions, the glass-ceramic exhibits the lowest Cr leaching concentration of 0.031 mg/L, far below the regulatory limit of 5 mg/L. The dominant crystalline phases are diopside and a spinel solid solution, where Cr 3+ is stably incorporated into the spinel. These findings demonstrate that controlled Na 2 O addition provides an effective compositional lever for optimizing both crystallization kinetics and heavy metal immobilization, offering a sustainable pathway for valorizing Cr-containing wastes into high-performance glass-ceramics.
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Zhuoqing An,Yuan Gao,Jiajing Chen
The CaO-MgO-Al 2 O 3 -SiO 2 (CMAS) glass-ceramics containing complex nucleation agents including La 2 O 3 and Fe 2 O 3 were prepared by melt process. The effects of these complex nucleation agents on the crystallization and microstructure of CMAS glass-ceramics were investigated through the thermal analysis (DSC), X-ray diffraction (XRD), optical microscopy, scanning electron microscopy (SEM) and Raman spectroscopy. The results indicated that the addition of La 2 O 3 and Fe 2 O 3 decreases viscosity and ion movement resistance. Furthermore, the La 2 O 3 can increase the crystallization peak temperature, while the Fe 2 O 3 has an inverse effect. The crystallization activation energy decreased from 298.87 to 264.26 kJ/mol as the mole ratio of La 2 O 3 increased to 2%. Conversely, when the mole ratio of Fe 2 O 3 increased to 2%, the crystallization activation energy increased from 298.87 to 347.21 kJ/mol. However, the addition of La 2 O 3 and Fe 2 O 3 decreased the Avrami parameter and promoted the surface crystallization within the CMAS glass system, as confirmed by the microstructure analysis. The crystal show branch-like crystal morphology when La 2 O 3 adding, whereas Fe 2 O 3 addition led to a compact, seaweed-like morphology with a fractal structure. With decreasing La 2 O 3 and increasing Fe 2 O 3 , the width of the dendritic branches increased. The major crystal phases detected on the surface were augite and diopside phase. Fe is predominantly present in the augite phase and La is primarily incorporated as a solid solution within the crystal phase.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）