CATALYSIS LETTERS
·
2020
·Vol. 150
·期 10
·2863-2872
·
IF 2.482
Zhang Pingbo,Chen Yifeng,Zhu Mengnan,Yue Chengguang,Dong Yuming,Leng Yan,Fan Mingming,Jiang Pingping
Magnetic mesoporous CoFe 2 O 4 @(CaO–ZnO) exhibited good catalytic activity in the transesterification of glycerol and dimethyl carbonate to yield glycerol carbonate. The glycerol conversion of 97.7% and glycerol carbonate yield of 96.9% could be obtained in this reaction system under the optimized reaction conditions. CoFe 2 O 4 @(CaO–ZnO) was characterized by a series of techniques including TPD, XRD, SEM, TEM, EDS, VSM and BET to evaluate the physico-chemical properties of the catalyst. It was demonstrated that the interaction of acid–base sites improved the catalysis performance of CoFe 2 O 4 @(CaO–ZnO): the strong basic sites were beneficial to the activation of glycerol to glyceroxide anion which could increase glycerol conversion, and the acid site contributes to the carbonyl activation of dimethyl carbonate, converts glyceroxide anion to glycerol carbonate, and improves the selectivity of glycerol carbonate. Meanwhile, the solid–liquid separation process after reaction would be simplified significantly considering CoFe 2 O 4 @(CaO–ZnO) could be easily separated from the reaction mixture under magnetic action. Graphic Abstract Acidic–basic bifunctional magnetic mesoporous CoFe 2 O 4 @(CaO–ZnO) was used as a solid base catalyst for the glycerol transesterification. Basic sites were beneficial to the activation of glycerol to glycerol oxygen anion to increase glycerol conversion and acidic sites were beneficial to carbonyl activation of DMC to increase glycerol carbonate selectivity. With magnetism, the solid base catalyst was easily recovered.
研究领域:
催化化学
·
材料科学
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产品关联
DOI
高影响因子
CHEMICAL PAPERS
·
2025
·
IF 2.5
Zhao Chun-Yan,Hu Xiu-Li,Zhou Wei
Calcium looping represents a high-temperature method designed to capture CO 2 , making it appropriate for CO 2 capture from flue gases post-combustion in power plants after combustion or for integration with fuel transformation techniques in pre-combustion CO 2 sequestration systems. This method employs solid sorbents of CaO sourced from natural limestone, leveraging the chemical interaction of CaO with CO 2 , which ultimately results in the formation of CaCO 3 , thereby facilitating effective CO 2 capture. In this research, multiple metal-incorporated CaO-based sorbents were produced through the sol–gel method. Notably, the CaO-based sorbent with a Ca/Ce doping ratio of 15 demonstrates exceptional CO 2 capture ability and stability, maintaining 13.20 mmol/g of CO 2 adsorption capacity after 20 carbonation/calcination cycles. Various characterization techniques, including X-ray diffraction (XRD), N 2 physisorption, scanning electron microscopy (SEM), high-angle annular dark field scanning transmission electron microscopy/energy dispersive spectroscopy (HAADF-STEM/EDS), temperature-programmed-desorption with CO 2 (CO 2 -TPD), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) are employed to demonstrate that the presence of nanoscale CeO 2 significantly enhanced the diffusion of CO 2 during the adsorption process.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2023
·Vol. 34
·期 7
·1-11
·
IF 2.8
Feng Jingmin,Zhang Yajuan,Lu Yang,Shan Yiting,Guo Xiang,Zhou Hongqing
In this study, CaO–B 2 O 3 –SiO 2 (CBS) glass–ceramics were prepared and compounded with different contents of ZrSiO 4 . The sintering behavior, phase composition, microstructure, dielectric properties, thermal properties, and mechanical properties of this CBS glass–ceramic composite ZrSiO 4 ceramic system were investigated. The results show that CBS glass–ceramic can be sintered densely at 750 °C. However, the crystallinity is unexpectedly low and the dielectric properties are greatly damaged. Surprisingly, the addition of ZrSiO 4 improved the dielectric constant of the composites and achieved a dielectric adjustable in the range of 6.0–7.8. When the composite was sintered at 830 °C for 15 min with 35% ZrSiO 4 addition, the bulk density of the composite increased to 2.93 g/cm 3 . The dielectric constant measured at a high frequency of 13 GHz was 6.93 and the dielectric loss of 1.66 × 10 –3 . Accordingly, the addition of ZrSiO 4 reduced the thermal expansion coefficient of the composite to 6.1 ppm/°C and increased the flexural strength of the composite to 248 MPa.
研究领域:
材料科学
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电子工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
·
IF 13.3
Rubin Zeng,Zhongjie Shen,Haigang Zhang,Yuxiang Cheng,Qinfeng Liang,Haifeng Liu
High-temperature sintering and solid-state reaction within the intricate Fe 2 O 3 /CaO system are pivotal factors influencing material characteristics. The current work focused on the sintering and reaction behavior of Fe 2 O 3 /CaO particles at high temperatures with a multiscale study of in-situ high-temperature stage microscopy (HTSM) and molecular dynamics (MD). The laws governing atomic migration and the evolution of crystal structure during the sintering process were simulated at the nanoscale. The results elucidated that a heightened heating rate fosters particle shrinkage and concomitant reduction in surface area. The sintering activation energy ( E sin ) exhibited an increment proportional to the linear shrinkage of the particles. Furthermore, an augmented potential barrier in advanced stages impeded subsequent sintering behavior. Augmented temperature promoted the particle shrinkage and sintering neck formation, culminating in pore closure and a diminution in the free surface. However, this promotional effect attenuated with escalating temperatures. Particle shrinkage and sintering neck formation are contingent upon atomic migration and diffusion, with the growth of sintering necks primarily reliant on atom diffusion along the surface of the sintering necks. The atomic diffusion activation energy was determined to be 49.5 kJ/mol within the temperature range of 1073–1473 K. Within the Fe 2 O 3 /CaO system, the preferential generation of Ca 2 Fe 2 O 5 (C2F) over CaFe 2 O 4 (CF) was found, leading to a decrease in the atomic diffusion barrier and an enhancement of the diffusivity, with the latter dominating in later stages. The highest mobility of O 2– , Fe 3+ , and Ca 2+ was discerned in CF, and the sintering shrinkage of the particles predominantly hinges on the generation of CF.
研究领域:
材料科学
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计算化学
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产品关联
DOI
高影响因子
ACS Catalysis
·
2023
·
IF 12.9
Yi Liu,Fanyu Wang,Fei Xie,Jiamin Zheng,Jintong Lan,Furong Guo,Yifei Sun,Lizhi Zhang,Xiao Liu
The degradation of chlorine-containing volatile organic compounds (Cl–VOCs) utilizing catalytic combustion technology is subject to the paradox of toxic byproduct formation and catalyst chlorine poisoning. Herein, a CaO-assisted strategy is proposed to resolve the awkward stuff for improving the catalytic combustion performance of chlorobenzene on SmMn2O5. The CaO-collaborated SmMn2O5 exhibits a significant decrease in T90 by 142 and 125 °C compared with unmodified and inert SiO2-composited SmMn2O5, respectively. The integrated characterization results confirm that CaO collaboration causes electron transfer from CaO to SmMn2O5, resulting in a reduction of the orbital overlap between Mn and O atoms to activate lattice oxygen (Olatt). The activated Olatt enables chlorobenzene to combust completely at a lower temperature of 275 °C at which toxic byproducts are not generated. Furthermore, the switching of the dechlorination site from SmMn2O5 to CaO avoids chlorine poisoning of active sites on SmMn2O5 and thus endows CaO-collaborated SmMn2O5 with prominent stability.
研究领域:
环境科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF IRON AND STEEL RESEARCH INTERNATIONAL
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2025
·
IF 3.6
Jin Hu-lin,Ma Yan,Wang Zhou-fu,Liu Hao,Dong Yun-jie,Yi Nian,Wang Xi-tang,Deng Cheng-ji,Xia Zhong-feng,Quan Zheng-huang,Zhang Ling,Tong Guang-da,Fu Wei-dong
MgO–CaO refractories have attracted much attention in the field of clean steel due to the ability of their internal CaO to adsorb elements such as S and P in molten steel. However, there are still some problems such as difficult sintering and insufficient corrosion resistance existing in this system. Different contents of Y 2 O 3 were introduced into MgO–CaO system to prepare MgO–CaO–Y 2 O 3 ternary refractories via traditional and induction sintering methods. The influence of microstructural regulation on the slag-resistant properties of the refractories was investigated. The results show that the introduction of Y 2 O 3 in the MgO–CaO refractories prepared via the two sintering methods leads to the grain boundary reconstruction effect. Under the condition of traditional sintering, when a smaller amount of Y 2 O 3 is introduced into the MgO–CaO refractories, Y 2 O 3 is able to activate the lattice, promote sintering, and improve the densification of the refractories. However, when more Y 2 O 3 is introduced, the excess Y 2 O 3 hinders the sintering densification process. Combined with lamellar intergranular phase generated in the refractories, Y 2 O 3 -based solid solution can react with the slag, increase the slag viscosity and inhibit the penetration of the slag into the refractories. Under the condition of induction sintering, the solid solution of yttrium ions in CaO is increased by using the coupling of electromagnetic and thermal fields. Compared with the MgO–CaO refractories with high Y 2 O 3 content prepared by traditional sintering, the induction sintered refractories have higher densification, which further increases the corrosion resistance. The results provide a new path for developing long-life MgO–CaO based refractories.
研究领域:
材料科学
·
陶瓷
·
冶金
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耐火材料技术
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Mengchuan Li,Tongsheng Zhang,Rensheng Li
The thermodynamic data of rare earth-containing systems are crucial for the development and application of permanent magnets, optoelectronic materials, high-temperature superconducting materials, and catalysts. In this study, the equilibrium phase compositions of the CaO-Ce 2 O 3 -SiO 2 -(5∼25 wt%) Al 2 O 3 system at 1873 K were investigated through high-temperature equilibrium experiments. The equilibrium phase compositions at 1873 K were determined using SEM, XRD, and EPMA, leading to the construction of isothermal sections. For the CaO-Ce 2 O 3 -SiO 2 -5 wt% Al 2 O 3 system, the isothermal cross-section diagram revealed a liquid phase region, four distinct two-phase equilibria, and two different three-phase equilibria. As the Al 2 O 3 content increased to 25 wt%, the isothermal cross-section diagram showed a liquid phase region, five different two-phase equilibria, and three distinct three-phase equilibria. The experimental results provide valuable insights for further research on the practical applications of cerium-containing rare earths in various fields.
研究领域:
材料科学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
SOLAR ENERGY
·
2019
·
IF 4.674
Azhar Abbas Khosa,C.Y. Zhao
CaCO 3 is a promising material for thermochemical energy storage (TCES) systems. It can store and release heat upon reversible decarbonation to CaO, which emits heat through carbonation. Decarbonation temperature of CaCO 3 directly affects the properties of CaO, which influences heat supply in result. The current research studies CaCO 3 /CaO system, specifically analyzing the conversion of CaO into CaCO 3 (carbonation) for various CaO samples prepared at decarbonation temperatures between 600 and 975 °C. A relation is developed using regression analysis to verify the linearity between reactivity of CaO samples and decarbonation temperature at which it was prepared. The carbonation of all CaO samples at various partial pressures of CO 2 and temperatures is also analyzed. The whole process is performed for pure and SiO 2 doped systems (molar ratio 1:1). The efficient performance of CaCO 3 /CaO system is noted for decarbonation temperatures above 750 °C or below 925 °C for pure material. While for doped material, the decarbonation temperature for efficient performance lies between 700 °C and 800 °C. Both systems performed with higher efficiency when CO 2 pressure was kept constant and the carbonation temperature was increased.
研究领域:
材料科学
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能源工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
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2024
·
IF 5.6
Chenlong Liu,Yijun Zhang,Yiman Xiao,Ruyue Zhang,Siddig Abuelgasim,Chenghua Xu,Atif Abdalazeez
Bio-oil by-products are inevitable with biomass gasification. It is considered a potential resource for hydrogen production via steam reforming. This study investigated acetic acid as a bio-model compound using a NiAl 2 O 4 catalyst. The effect of reaction conditions on hydrogen-rich production has also been discussed, including reaction time (1 h, 3 h, 5 h and 7 h), steam/carbon ratio (S/C = 1–4) and the blend of NiAl 2 O 4 and CaO (1:0, 3:1, 1:1, 1:3 and 0:1). The fresh and spent samples were characterized by XRD, XPS, SEM, BET, etc. The result showed that the CaO addition has several advantages: 1) it increases hydrogen gas purification; 2) it prevents Ni separation from NiAl 2 O 4 ; 3) it decreases the sintering of NiAl 2 O 4 . However, Ca 5 Al 6 O 14 formation decreases the activity of hydrogen production. In reaction conditions, steam is an essential factor for hydrogen gas production. The S/C ratio = 3 shows the optimum result for hydrogen gas production. Although the higher S/C ratio = 4 can maintain the adsorption activity of CaO, it causes Ni separation from NiAl 2 O 4 . The blend of NiAl 2 O 4 and CaO is another essential factor for hydrogen gas production. Adding CaO has increased hydrogen gas production significantly. However, a little CaO in a blend ratio 3:1 does not maintain the stability of the NiAl 2 O 4 structure. In the end, the optimum conditions are S/C ratio = 3 and blend = 1:1 at 650 °C, which produces hydrogen gas yield (2.1 mol/mol) and H 2 /CO (5.83).
研究领域:
能源科学
·
催化化学
✓ 已验证
DOI
高影响因子
HIGH PRESSURE RESEARCH
·
2018
·
IF 1.925
Akun Liang,Yinjuan Liu,Hao Liang,Fangming Liu,Cong Fan,Jiawei Zhang,Jinjun Wu,Ji Chen,Duanwei He
The thermal insulation performance of cubic ZrO2–CaO solid solution (CSZ) (16 mol % CaO) and monoclinic ZrO2 (MZ) was investigated in a two-stage multi-anvil press under a pressure of 10 GPa and temperatures up to 1800°C through in situ temperature measurements with the same cell assembly. The results show that the cell temperatures with CSZ as the thermal insulator were always higher than that when thermal insulator was MZ at the same heating power, and the maximum deviation value was 600°C (50% higher) within the measurable range. These two materials were analyzed using X-ray diffraction (XRD), thermal conductivity measurement and scanning electron microscopy. It revealed that the point defects existed in CSZ dominated the thermal insulation performance at high pressure, the same as what at normal pressure. It was also found that the heating process was more controllable when using CSZ as thermal insulator under high pressure.
研究领域:
材料科学
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热物理
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
·
IF 8.1
Yu Fan,Bowen Lu,Ziqiang Han,Cong Luo,Liqi Zhang
CeO 2 support inhibits CaO sintering, and oxygen vacancy influences CO 2 hydrogenation performance, making CeO 2 widely applied in Integrated CO 2 capture and in-situ conversion technology for reverse water–gas shift (ICCC-RWGS). Oxygen vacancy concentration was dependent on the morphology of CeO 2 , which would affect metal dispersion and CO 2 hydrogenation conversion. However, Very little is known about the morphology effect of CeO 2 on the carbon capture and in-situ hydrogenation performance of DFMs. Here, Cu/CeO 2 with different CeO 2 morphologies was synthesized, and high Cu dispersion was achieved on Cu/CeO 2 -R, exhibiting the best CO 2 hydrogenation performance. Integrated Cu/CeO 2 with CaO by physical mixing method, CaO-Cu/CeO 2 was used to investigate the morphology effects of CeO 2 on the performance of CaO-Cu/CeO 2 for integrated CO 2 capture and conversion to CO. CaO-Cu/CeO 2 -R exhibited the best capture-hydrogenation performance (CO 2 conversion rate of 75 %, CO production rate of 9.72 mmol/g). The CeO 2 -R provided more surface oxygen vacancies, enhancing carbonate hydrogenation. The larger specific surface area and {1 1 0} crystal plane of CeO 2 -rod enhanced Cu dispersion, and the smaller particle size of CeO 2 -R enhanced its interaction with CaO, improving the cyclic stability of CaO-Cu/CeO 2 -R. The hydrogenation performance of CaO-Cu/CeO 2 was dependent on the morphology of CeO 2 , providing insights into the design of high-activity metal catalytic components in ICCC-RWGS.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
RENEWABLE ENERGY
·
2020
·
IF 6.274
Yujiao Zhang,Shengli Niu,Kuihua Han,Yingjie Li,Chunmei Lu
Calcium oxide is one of the most promising heterogeneous catalysts for biodiesel production . However, an inherent drawback of CaO is the leaching of active species into the reaction solution with the degraded reusability . To strengthen the stability, different supports are composited with the SrO–CaO oxide through the hydrothermal method and mass ratio of SrO to CaO are optimized to get the best outcome of the catalyst. Meanwhile, various characterization methods, including TG , XRD , SEM-EDX, CO 2 -TPD, XPS , ATR-FTIR and ICP-AES, are used to explore the physicochemical properties of catalysts. The 0.4-SrO-CaO-Al 2 O 3 catalyst shows the best catalytic capability in transesterification of palm oil with methanol to produce biodiesel , where the FAME yield of 98.16% is achieved with the molar ratio of methanol to oil of 18:1 and catalyst concentration of 7.5 wt% at 65 °C for 3 h. Besides, ascribed to the greatly reduced leaching out of the active species , this catalyst presents the satisfying reusability and the FAME yield is slightly decreased to 92.61% for the fifth reused cycle. Therefore, this modification method for SrO–CaO–Al 2 O 3 is feasible for enhancing the catalytic stability in transesterification .
研究领域:
催化化学
·
可再生能源
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）