METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
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2024
·
IF 2.4
Chen Mao,Chen Buxin,Jiang Yang,Zheng Kui,Hu Meilong,Qiu Shuxing
Ti(C,N) is commonly observed in vanadium titanomagnetite blast furnaces and greatly affects the stable and smooth operation of the smelting processes. To get fundamental insight into Ti(C, N) formation, systematic experiments were conducted to investigate the effects of the composition of slags, temperatures, reaction time and reaction atmosphere on the formation of Ti(C,N) from TiO 2 -containing slags. The results show that TiN and TiC contents increase with TiO 2 content increases. When TiO 2 is larger than 30 wt pct, TiN contents increase dramatically. Control of basicity, MgO and Al 2 O 3 concentrations in the slag could help to reduce Ti(C,N) contents in slags. TiN and Ti(C,N) contents increase dramatically with the extension of time. TiN is more easily formed at high temperatures, and TiN contents increase with the increase of temperature. With the increase of N 2 contents, TiC contents are relatively stable, and TiN and Ti(C,N) contents increase almost linearly. H 2 would greatly promote the formation of TiC. This paper can provide a theoretical basis for minimizing the formation of Ti(C,N) in different blast furnace conditions.
研究领域:
冶金学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Open Ceramics
·
2023
·
IF 0
Zhaoju Yu,Zhenyue Wang,Xichao Dong,Jia Sun,Xingang Luan,Ralf Riedel
Liquid polymeric precursors have found wide applications as a matrix source for continuous fiber reinforced ceramic matrix composites (CMCs) because of their excellent fluidity and high ceramic yield. In the present study, a processable liquid single-source-precursor was synthesized using allylhydropolycarbosilane (AHPCS) and low-cost hafnium tetrachloride (HfCl 4 ) as raw materials to form final SiC-HfC-C nanocomposites by well-known polymer-derived ceramic (PDC) approach. The precursor synthesis, thermal behavior, polymer-to-ceramic transformation and ceramic phase evolution were investigated by FT-IR, TGA, XRD and TEM. The TGA results show that the obtained single-source-precursor exhibits very high ceramic yields of over 80.0 wt% after heat treated at 1400 °C. After annealing at 1600 °C, the resultant SiC-HfC-C nanocomposites contain SiC@C and HfC@C nanoparticles with SiC and HfC as cores and amorphous carbon as shells. The present single-source-precursor is candidate material for CMC applications due to its liquidity and high ceramic yield.
研究领域:
材料科学
·
陶瓷材料
✓ 已验证
DOI
SYNTHETIC COMMUNICATIONS
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2018
·
IF 1.377
Xinyuan Ma,Qiong Mo,Jie Chang,Kai Xie
This paper mainly studied Pd-catalyzed regioselective chlorination of disubstituted 1,2,3-triazoles directed by the 1,2,3-triazole ring. A series of regioselective chlorinated products were synthesized in 47–86% yields using Pd(OAc)2 as a catalyst and CuCl2 as a chlorinated reagent. This method provides a new mean for the synthesis of 1,2,3-triazole halides which combines the formation of C-X bond with C-H activation.
研究领域:
有机化学
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合成化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Minghua Wang,Dan Guo,Bochong Wang,Jianyong Xiang,Kun Zhai,Tianyu Xue,Fusheng Wen,Yingchun Cheng,Congpu Mu
In this work, MIL-96 (Ga) was successfully synthesized by a microwave-assisted method and pyrolyzed at 700 o C to obtain Ga 2 O 3 /C (G-700) composites. After carbonization, Ga 2 O 3 nanoparticles were uniformly embedded in a porous carbon skeleton. The surface of MIL-96(Ga)-derived Ga 2 O 3 /C was used as a template for directional pyrrole polymerization. G-700@PPy composite materials were obtained by in-situ polymerization of pyrrole on the surface of G-700. A hierarchical interfacial structure was created with regulated dielectric properties. The effect of pyrrole doping content on the electromagnetic waves (EMWs) absorption properties of G-700@PPy composite materials was studied. The experimental result showed that the minimum reflection loss ( RL min ) value of G-700@PPy-3 composite materials reached -79.0 dB under a thin thickness of 1.58 mm, and the maximum effective absorption bandwidth (EAB) of 5.66 GHz was obtained under 1.78 mm. The results indicate that highly conductive PPy could significantly improve the impedance matching conditions and electromagnetic attenuation capacity of G-700 composite materials, which provided an important idea for optimizing the microwave absorption properties of low permittivity composites.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
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2017
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IF 4.849
Jian Cheng,Jun Sun,Jiekuan Yan,Song Yang,Pengcheng Zheng,Zhichao Jin,Yonggui Robin Chi
The metal-free catalytic functionalization of aromatic sp2-carbons and benzylic sp3-carbons remains challenging. Here we report a carbene-catalyzed functionalization of the 3-methyl sp3-carbon attached to 2-formyl-indoles. The reaction proceeds through an NHC-bound o-quinodimethane as the key intermediate generated from 2-formyl-3-methylindoles under oxidative conditions. Reactive ketones are found to be effective substrates to produce substituted hydropyrano[3,4-b]indoles in good to excellent yields.
研究领域:
有机化学
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合成化学
✓ 已验证
DOI
高影响因子
ADVANCED ENGINEERING MATERIALS
·
2024
·
IF 3.4
Yufei Huang,Jia Zhao,Guojing Chen,Xuhui Han,Chunpeng Chai,Huiling Ma
Thin-thickness and lightweight electromagnetic wave (EMW) absorption materials are critically needed for stealth technology in the military stealth field. The special structure of a material is important for improving its good EMW absorption. Herein, a series of porous metal–organic framework-derived LaCo/C-decorated Ti 3 C 2 T x (LaCo/C/Ti 3 C 2 T x ) composites are prepared by carbonization at high temperatures. Impressively, the minimum reflection loss of LaCo/C/Ti 3 C 2 T x –2 is −47.72 dB at 10.26 GHz (thickness 2.3 mm), and the optimal effective absorption bandwidth is 5.45 GHz (thickness 1.9 mm). The excellent EMW absorption properties are due to multiple electromagnetic loss mechanisms, such as polarization loss, magnetic loss, and multiple reflections and scattering. This work provides a new route for the application of Ti 3 C 2 T x -based derivatives.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
IONICS
·
2012
·Vol. 19
·期 3
·529-534
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IF 1.288
Wang Wei,Wang Hui,Key Julian,Linkov Vladimir,Ji Shan,Wang Rongfang
To improve the electrocatalytic properties of PtRu/C in methanol electrooxidation, nanoparticulate TiO 2 -promoted PtRu/C catalysts were prepared by directly mixing TiO 2 nanoparticles with PtRu/C. Using cyclic voltammetry, it was found that the addition of 10 wt% TiO 2 nanoparticles can effectively improve the electrocatalytic activity and stability of the catalyst during methanol electrooxidation. The value of the apparent activation energy ( E
a ) for TiO 2 -PtRu/C was lower than that for pure PtRu/C at a potential range from 0.45 to 0.60 V. A synergistic effect between PtRu and TiO 2 nanoparticles is likely to facilitate the removal of CO-like intermediates from the surface of PtRu catalyst and reduce the poisoning of the PtRu catalysts during methanol electrooxidation. Therefore, we conclude that the direct introduction of TiO 2 nanoparticles into PtRu/C catalysts offers an improved facile method to enhance the electrocatalytic performance of PtRu/C catalyst in methanol electrooxidation.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
Chemistry-An Asian Journal
·
2018
·Vol. 14
·期 3
·416-421
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IF 3.692
Qian Wang,Wei Sun,Tianying Xie,Limei Cao,Ji Yang
Graphical Carbon-coated catalysts : Octahedral Pt/ZrO 2 @C, prepared by direct carbonization of the precursor UiO-66-NH 2 (a zirconium-based metal–organic framework), exhibits improved catalytic activity for selective catalytic reduction with H 2 at ambient temperature, compared with that of other platinum-based catalysts with porous materials as supports (see figure). Selective catalytic reduction (SCR) of NO x with H 2 as a reductant is the most promising denitration technology at low temperature. Achieving the conversion of NO x into N 2 at ambient temperature not only prolongs the service life of the catalyst, but also provides more freedom for the arrangement of denitration units throughout the flue gas treatment equipment. However, the development of highly efficient, stable, and environmentally benign supported platinum-based catalysts for H 2 -SCR at ambient temperature is still a major challenge. Herein, a 0.5 wt % Pt/ZrO 2 @C catalyst, which was composed of carbon-coated octahedral ZrO 2 with highly dispersed Pt particles, was prepared by using a new stabilization strategy based on UiO-66-NH 2 (a zirconium metal–organic framework) as a template. The catalytic performance of this Pt/ZrO 2 @C in H 2 -SCR was tested and confirmed to achieve near 100 % NO x conversion at 90 °C. Also, 70 % N 2 selectivity of the catalyst was achieved. The morphology, structure, and porous properties of the as-synthesized nanocomposites were characterized by using data obtained from field-emission SEM, TEM, XRD, Raman spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, and N 2 adsorption–desorption isotherms. The results show that residual carbon formed by pyrolysis treatment is coated on octahedral ZrO 2 , and effectively prevents the agglomeration of platinum particles on the surface.
研究领域:
化学工程
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材料科学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
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2024
·
IF 4.4
Xuyong Tang,Fengxi Li,Sijun Huang,Li Xu,Lei Wang,Yi Guo
Nicotinamide-adenine dinucleotide (NADH) as biomimetic units combined with copper ion to form laccases mimics (Cu-NADH). Cu-NADH has the enhanced activity of copper center to mediate aryl C–H amination using air as green oxidants. It could successfully catalyze oxidative coupling between different aromatic compounds and 4-phenylurazole (yield: 72 ∼ 91 %). Recycling catalytic ability (up to 6 times) showed its excellent stability. The Cu-NADH nanozyme was certificated to catalyze C–H amination effectively, and highlighted that it was a proper way to design catalysts according to enzyme-like catalyzing non-natural reaction.
研究领域:
生物化学
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催化化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Wei Song,Hanqing Zhao,Jianqi Ye,Mengmeng Kang,Siyu Miao,Zhong Li
Ti–O–C channels for ultrafast sodium storage were constructed in N/S-co-doped TiO2–C nanofibers, which deliver a high rate performance of 181.9 mAh g–1 at 5 A g–1 after 3000 cycles. The existence of Ti–O–C bonds at the interface of TiO2–C phases was revealed by synchrotron radiation X-ray absorption spectra. Based on this, first-principles calculations further verified the low energy barrier for Na+ insertion/extraction in the Ti–O–C channels formed by the intimately integrated graphite layer with TiO2 near the surface. In addition, surface defects induced by heteroatoms accelerate the Na+ mass transfer through the pathway from the carbon surface to the Ti–O–C channel.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Na Ye,Pengcheng Zhao,Xiaoying Qi,Wenchao Sheng,Zhao Jiang,Tao Fang
The C C bond cleavage remains a main challenge for alkaline EOR (ethanol oxidation reaction). In this work, we report an efficient PdSn-TaN/C electrocatalyst to split the C C bonds in ethanol. Structurally, a series of characterization results confirm the presence of the low-coordinated Pd sites on the PdSn-TaN/C interface. The PdSn-TaN/C catalyst exhibits very high activity (almost 26.9 times of commercial Pd/C), good durability and high selectivity to CO 2 (20.5%) towards alkaline EOR. Specifically, in-situ ATR-SEIRAS (Attenuated total reflection-surface enhanced infrared absorption spectroscopy) results indicate that TaN facilitates the cleavage of C C bonds, whereas Sn promotes the further oxidation of ethanol fragments. DFT (density functional theory) calculations indicate the activation barriers of the C H bond cleavage in CH 3 CH 2 OH, CH 3 CHOH, CH 3 CHO, CH 3 CO, CH 2 CO and the C C bond cleavage in CH 3 CO, CH 2 CO, CHCO are reduced evidently and the removal of adsorbed CH 3 CO and CO becomes easier on the PdSn-TaN/C catalyst surface.
研究领域:
电化学
·
催化材料
·
理论计算
✓ 已验证
DOI
高影响因子
International Journal of Electrochemical Science
·
2024
·
IF 1.3
Lin Zhu,He-ying Xia,Chun-yong Zhang,Ying Geng,Zhe Li,Li Shu,Ji-rong Bai,Ying-pin Wen
As a new type of efficient electrochemical energy storage system, the supercapacitor serves as an effective means to support the development of clean energy, with the electrode material being the key determinant of performance. The electrode material Pt-NiCo 2 O 4 /C was prepared in this paper by stepwise hydrothermal and calcination methods using ZIF-67 as a template, aiming to improve specific capacitance performance and stability. Pt-NiCo 2 O 4 /C achieved a specific capacitance of 1665.3 F/g at a current density of 1.0 A/g, and maintained 94.49% of the original specific capacity after 3500 cycles at a current density of 4.0 A/g. The excellent specific capacitance performance of the Pt-NiCo 2 O 4 /C electrode material makes it a promising potential candidate for energy storage applications.
研究领域:
材料科学
·
能源存储技术
✓ 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）