ADVANCED MATERIALS
·
2023
·
IF 29.4
Wenzheng Zhang,Mingyi Tan,Daming Chen,Boqian Sun,Yuan Cheng,Liancai Xun,Jingsheng Hu,Chenlin Hou,Yuxuan Liu,Yuhao Fang,Ping Hu,Wenbo Han,Shun Dong,Shanyi Du,Jiecai Han,Shuxi Miao,Qidong Yang,Yanchun Zhou,Xinghong Zhang
Sugars are renewable resources essential to human life, but they are rarely used as raw materials for the industrial production of carbon-based materials, especially for the preparation of carbon fiber-reinforced carbon-matrix (C/C) composites, which are extremely useful for the semiconductor and aerospace sectors. Herein, a method utilizing sugar-derived carbon to replace petrochemicals as dense matrix to preparing C/C composites is reported. The matrix from sugar-derived C/C (S–C/C) composites has a nanocrystalline graphite structure that is highly thermally stable and effectively bonded to the carbon fibers. The mechanical properties of the S–C/C composite are comparable to those prepared from petrochemical sources; significantly, it exhibits a linear ablation rate of 0.03 mm s −1 after 200 s of ablation at 3000 °C in 10 MW m −2 heat flux. This new class of S–C/C is promising for use in a broad range of fields, ranging from semiconductor to aerospace.
研究领域:
材料科学
·
航空航天工程
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产品关联
DOI
PubMed
高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2019
·
IF 2.338
Li-ping RAN,Fei RAO,Ke PENG,Huan YIN,Mao-zhong YI
Ultrahigh-temperature ceramics were added to C/C composites to meet their application requirement in a high-temperature oxidizing environment. C/C−ZrB 2 −SiC composites were fabricated by high-solid-loading slurry impregnation with polymer infiltration and pyrolysis. The dispersion and rheological behavior of ZrB 2 slurry and the microstructural, mechanical, and ablation properties of the C/C−ZrB 2 −SiC composites were investigated. Results indicated that a well-dispersed and low-viscosity ZrB 2 slurry was obtained using 0.40 wt.% polyethyleneimine as a dispersant at pH 5. Ceramics were uniformly distributed in the short-cut fiber layer and needle-punched area. The flexural strength of the C/C−ZrB 2 −SiC composites was 309.30 MPa. The composites exhibited satisfactory ablation resistance under the oxyacetylene flame of 2500 °C, and the mass and linear ablation rates were 0.40 mg/s and 0.91 μm/s, respectively. A continuous and compact ZrO 2 layer, which could effectively reduce the diffusion rate of oxygen and protect the composites from being ablated, was formed.
研究领域:
材料科学
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航空航天工程
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产品关联
DOI
高影响因子
ACS Catalysis
·
2017
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IF 10.614
Tingting Hou,Nengchao Luo,Hongji Li,Marc Heggen,Jianmin Lu,Yehong Wang,Feng Wang
Selective cleavage of C–C bonds is pursued as a useful chemical transformation method in biomass utilization. Herein, we report a hybrid CuOx/ceria/anatase nanotube catalyst in the selective oxidation of C–C bonds under visible light irradiation. Using the lignin β-1 model as a substrate offers 96% yields of benzaldehydes. Characterization results by high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) and energy-dispersive X-ray spectroscopy element (EDX) mapping reveal that CuOx clusters are highly dispersed on the exposed anatase surface as well as on the nanosized ceria domains. In-depth investigations by Raman and ultraviolet visible diffuse reflectance spectra (UV−vis DRS), together with density functional theory (DFT) calculations, further verify that the CuOx clusters present on the ceria domains increase the concentration of surface defects (Ce3+ ions and oxygen vacancies) and accordingly improve the photocatalytic activity (Yang character); the CuOx clusters decorating on anatase suppress the side reaction (oxy-dehydrogenation without C–C bond cleavage) because of an upward shift in the valence band (VB) edge of anatase (Yin character). Mechanism investigation indicates hydrogen abstraction from β-carbon by photogenerated holes is a vital step in the conversion.
研究领域:
化学
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材料科学
·
催化反应
✓ 已验证
DOI
高影响因子
ADVANCED SYNTHESIS & CATALYSIS
·
2017
·Vol. 359
·期 3
·454-466
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IF 5.646
Xu Cheng,Weijian Li,Ruifang Nie,Xiaojun Ma,Rui Sang,Li Guo,Yong Wu
A micron-scale palladium(II) material has been successfully prepared using Schiff base-modified hexagonal boron nitride as a support and used for the first time as an efficient and recyclable catalyst in organic synthesis. The morphology, composition, metal loading and thermal stability of the catalyst were studied using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), infrared spectroscopy (FT-IR), inductively coupled plasma (ICP) and thermogravimetric (TG) analyses. Then, the micron material was tested in various C–C cross-coupling reactions and exhibited excellent catalytic activities in the Suzuki and Heck reactions. Moreover, the catalyst could be easily recovered by simple filtration and reused at least ten times without significant loss of its catalytic activity. In general, this work demonstrates the possibility of using Schiff-base@hexagonal boron nitride as an efficient support for heterogeneous catalysts.
研究领域:
有机化学
·
催化材料科学
✓ 已验证
DOI
高影响因子
Reaction Chemistry & Engineering
·
2024
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IF 3.4
Shaoyuan Guo,Xinli Tong,Jipeng Wang,Hang Tang
The use of high-entropy oxides (HEOs) in heterogeneous catalysis is a fascinating research direction in the chemical field. In this work, a highly selective aerobic oxidative C–C bond cleavage using a 1,2-diol and lignin model is achieved with the HEOs-derived multimetallic catalyst. In the transformation of 1-phenyl-1,2-ethanediol, a 96.1% conversion with 96.2% selectivity of benzaldehyde was obtained using MgCuMnFeCo–R as the catalyst. Therein, the partial reduction of Fe2+ and Co2+ leading to the formation of numerous oxygen vacancies, plays a crucial role in the excellent catalytic activity. Moreover, this HEO-derived catalyst could maintain high activity even after being reused more than 10 times.
研究领域:
化学
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2024
·Vol. 14
·期 4
·973-979
·
IF 4.4
Peidong Ren,Lei Shi,Ziwang Kan,Jiaxiao Bai,Yunyi Liu,Shucheng Yang,Siqi Li,Song Liu
The electrochemical conversion of lignin for the production of high-value aromatic compounds holds immense potential. However, the process of depolymerizing lignin faces significant challenges due to its intricate structure, particularly the existence of C–C bonds, resulting in low conversion and product yields. In this work, we report the successful synthesis of a molecular palladium catalyst and its inaugural application in the electrochemical conversion of lignin model compounds. This catalyst with well-defined coordination structure demonstrates exceptional efficacy and achieves a remarkable 99% conversion rate for the lignin model compound 2-phenoxy-1-phenylethanol with a yield of 32% of the benzaldehyde product while valuable hydrogen is produced at the electrode under ambient conditions. Furthermore, employing radical trapping and EPR test point that the tBuO˙ radical was the key to inducing C–C cleavage for high conversion and enabled a comprehensive elucidation of the possible reaction pathways involving radical/radical cross-coupling. Based on this study, we believe that molecular catalysts will open a new chapter in the electrocatalytic conversion of lignin.
研究领域:
化学
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能源科学
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2020
·Vol. 11
·期 1
·1-11
·
IF 12.121
Cao Wenbo,Cheng Simin,Yang Jing,Feng Jiaxin,Zhang Wenpeng,Li Zishuai,Chen Qinhua,Xia Yu,Ouyang Zheng,Ma Xiaoxiao
Lipids play a pivotal role in biological processes and lipid analysis by mass spectrometry (MS) has significantly advanced lipidomic studies. While the structure specificity of lipid analysis proves to be critical for studying the biological functions of lipids, current mainstream methods for large-scale lipid analysis can only identify the lipid classes and fatty acyl chains, leaving the C=C location and sn -position unidentified. In this study, combining photochemistry and tandem MS we develop a simple but effective workflow to enable large-scale and near-complete lipid structure characterization with a powerful capability of identifying C=C location(s) and sn -position(s) simultaneously. Quantitation of lipid structure isomers at multiple levels of specificity is achieved and different subtypes of human breast cancer cells are successfully discriminated. Remarkably, human lung cancer tissues can only be distinguished from adjacent normal tissues using quantitative results of both lipid C=C location and sn -position isomers.
研究领域:
生物化学
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医学
·
质谱学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Today Sustainability
·
2023
·
IF 7.8
G. Yang,H. Sun,R. Liu,J. Shi,X. Tong
Heterogeneous catalytic and selective C–C bond cleavage is considered as the important way for the production of high valuable compounds from large-molecule-weight feedstock . In this article, a sustainable and efficient aerobic oxidative C–C bond cleavage of lignin models is developed with the bismuth-based solid catalyst. Therein, the flower-like Bi 2 O 2 CO 3 exhibits a high photocatalytic efficiency in the reaction medium combined of n-butanol and tetramethylammonium bromide. For example, the selective oxidative C–C bond cleavage of 1-phenyl-ethane-1, 2-diol has been successfully carried out, where the substrate conversion and the selectivity of benzaldehyde was 95% and 99%, respectively. The study exhibited that the amount of oxygen vacancies plays a significant role on the photocatalytic selective aerobic oxidative cleavage processes. Moreover, the selective aerobic oxidative C–C bond cleavage of different lignin models was investigated, and all the yields of corresponding products are more than 90% with this photocatalytic system. Furthermore, the used flower-like Bi 2 O 2 CO 3 can be recycled at least 5 times without the obvious decrease of catalytic activity .
研究领域:
催化化学
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环境科学
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产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
·
IF 5.7
Aolin Xie,Bei Zhang,Yicheng Ge,Ke Peng,Ping Xu,Xiaodong Wang,Zhirong Feng,Maozhong Yi,Zhe Zhou
To maintain the thermal stability of SiC nanowires during SiC coating fabrication process, carbon and SiC double protective layers were covered on the surface of nanowires. And SiC nanowires with double protective layers toughened SiC coating were prepared by pack cementation. The results showed that after introducing the SiC nanowires with double protective layers, the fracture toughness of the SiC coating was increased by 88.4 %. The coating protected C/C for 175 h with a mass loss of 3.67 %, and after 51 thermal shock cycles, the mass losses of the oxidized coating were 3.96 %. The double protective layers are beneficial to improve the thermal stability of nanowires, leading to good fracture toughness and thermal shock resistance of SiC coating. SiC nanowires consume the energy of crack propagation by fracture, pullout and bridging, leading to an increase in fracture toughness.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Research
·
2022
·
IF 11.036
Hai-Fang Li,Jing Zhao,Wenbo Cao,Wenpeng Zhang,Yu Xia,Zheng Ouyang
Unraveling the complexity of the lipidome requires the development of novel approaches to facilitate structural identification and characterization of lipid species with isomer-level discrimination. Ultraviolet photodissociation tandem mass spectrometry (UVPD MS/MS) is a promising tool for structure determination of lipids. The sensitivity of UVPD for lipid analysis however is limited mainly due to weak absorption of UV photons by a C=C. Herein, a C=C site-specific derivatization, the Paternò-Büchi (PB) reaction, was used to incorporate a chromophore to the C=C moiety in fatty acyls, leading to significantly improved UVPD efficiency and sensitivity for pinpointing C=C locations. The wavelength-dependent photodissociation of the PB products demonstrated 4-CF3-benzophenone as the best reagent for UVPD in terms of the efficiency of generating C=C diagnostic fragments and simplicity for C=C location assignments. We demonstrated the effectiveness of this approach for the shotgun profiling of C=C location isomers in different lipid classes from complex lipid extracts, highlighting its potential to advancing the identification of the C=C bond locations in unsaturated lipids.
研究领域:
生物化学
·
分析化学
·
质谱技术
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2016
·
IF 2.628
Zhifeng Dai,Fang Chen,Qi Sun,Yanyan Ji,Liang Wang,Xiangju Meng,Feng-Shou Xiao
An efficient catalyst system based on a Pd-metalated porous organic polymer bearing phenanthroline ligands was designed and synthesized. This catalyst was applied to various C–C bond-forming reactions, including the Suzuki, Heck and Sonogashira couplings, and afforded the corresponding products while exhibiting excellent activities and selectivities. More importantly, this catalyst can be readily recycled. These features show that such catalysts have significant potential applications in the future.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Yanyan Wang,Jiaping Liao,Zunyuan Xie,Kan Zhang,Ya Wu,Ping Zuo,Weiqiang Zhang,Jiyang Li,Ziwei Gao
Supported palladium catalysts have attracted significant attention for use in cross-coupling reactions due to their recyclability. However, the inevitable progressive loss of Pd that occurs in the catalytic process deactivates the catalysts, which hinders their sustainable application. Herein, we report a zeolite-enhanced sustainable Pd catalyst for C–C cross-coupling reactions. Zeolite does a good job of acting as a sink for Pd2+ ions. This catalyst exhibits an excellent homogeneous catalytic performance by releasing Pd species from zeolite. In addition, the Pd2+ ions were successfully recaptured in a controlled catalytic system by combining the uniform microporous structure and good adsorption features of zeolite. The release/capture mechanism of the Pd species guaranteed the high loading and high dispersion of Pd on the recycled catalyst. The 0.84%Pd@USY catalysts were reused at least 10 times in water without an appreciable reduction in activity. This study presents a new perspective toward the design of a highly efficient and sustainable supported metal catalyst.
研究领域:
化学工程
·
催化科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）