GREEN CHEMISTRY
·
2023
·Vol. 25
·期 13
·5150-5159
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IF 9.8
Yuzhen Hu,Yanbin Cui,Shuoxiao Zhao,Xuelai Zhao,Xiaohong Hu,Zhenlong Song,Wei Fan,Qi Zhang
Selective cleavage of C–C bonds in the lignin structure is crucial for the depolymerization of lignin and producing value-added chemicals. In this study, we reported that Pd/CeO2 catalysts can selectively catalyze the Cα–Cβ bond cleavage of oxidized lignin model components and authentic lignin in an aqueous phase under mild conditions (50 °C, ambient pressure). A variety of β-O-4 and β-1 ketones with representative Cα–Cβ bonds were successfully cleaved yielding aromatic acids and phenols in 76.8–94.9% yields. Their unique catalytic properties are derived from the electron transfer between Pd and CeO2 support which facilitates active Pd2+ sites and reactive oxygen species formation. A mechanistic study elucidates that base-mediated C–H bond activation via enolization and in situ reactive oxygen species (˙O2−) formation are the key steps for the selective Cα–Cβ cleavage. Furthermore, the applicability of the system for the bond cleavage in an authentic lignin sample was demonstrated. Nearly 54.2 wt% of oxidized bamboo lignin was converted, generating aromatic monomer yields up to 35.9 wt%, with a high selectivity for aromatic aldehydes.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
Molecular Catalysis
·
2025
·
IF 4.9
Wei Wang,Rui Zhang,Jiaqing Li,Huai Liu,Wenlong Jia,Junhua Zhang,Dan Li,Lincai Peng
Furans are important scaffolds with applications in pharmaceuticals, polymers synthesis and biofuels. The direct production of new types of furans from glucose is therefore significant but remains a great challenge. Herein, we report a facile strategy to produce acetylfurans directly from glucose over MoCs-SiO 2 , with an increase in yield from 35.8 % to 81.4 % compared with pristine Mo-SiO 2 due to the facilitated C−C bond cleavage of glucose. The incorporation of Cs improved the dispersion of Mo species, induced the formation of partially reduced Mo, increased the Lewis acidity and glucose adsorption of the catalyst, and thus shifting the reaction selectivity from C−C coupling to cleavage. Kinetic studies further demonstrated the positive contribution of Cs as a promoter in lowering the activation energy of C−C bond cleavage. This study provides a promising strategy to broaden the range of furanic compounds derived from glucose for product-oriented biorefineries.
研究领域:
化学工程
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生物催化
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可再生资源利用
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产品关联
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2018
·Vol. 56
·期 20
·2344-2353
·
IF 2.588
Jiajun Bi,Jian Chen,Yahao Dong,Wen Guo,Dajian Zhu,Tao Li
A new polymer was prepared from 1,3,5-triformylphloroglucinol (noted as TDTB) and o -phenylenediamine through Schiff base condensation reaction, and palladium (II) was immobilized on the polymer (noted as TbPo-Pd(II)). This process was easy to work-up and cost-effective. The structure and composition of TbPo-Pd(II) were fully characterized by FTIR, TGA, XPS, AAS, SEM, and TEM analyses. Meanwhile, this catalyst showed desired thermal stability and excellent performance in water/methanol system for Suzuki and Sonogashira coupling reactions. In addition, this heterogeneous catalyst can be readily recovered by simple filtration with no appreciable Pd leaching in the reaction. This work provides a powerful protocol for rapid access to asymmetrical biphenyls and aryl alkynes. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56 , 2344–2353
研究领域:
有机化学
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材料科学
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Jiayuan Sun,Shanshan Shao,Xinggang Hu,Xiaohua Li,Huiyan Zhang
The aqueous fraction of bio-oil from biomass fast pyrolysis mainly contains low-molecular-weight oxygenates such as carboxylic acids, ketones, aldehydes, phenols, and furans. In this study, the full components of aqueous bio-oil are directionally converted into carbonyl groups such as aldehydes and ketones, and then the oxygen-containing precursors of aviation fuel are prepared through coupling, focusing on exploring the mechanism of carbonylation and C–C coupling. Studies have revealed that propionic acid, furfural, and phenol can be directionally converted into ketones, in which reaction 3-pentanone, cyclopentanone, and cyclohexanone were formed via ketonization and hydrogenation in the aqueous phase. Then the two components of 3-pentanone, cyclopentanone, cyclohexanone, acetone, and acetaldehyde were subjected to aldol condensation to explore the C–C coupling mechanism in the preparation of the C7–C18 precursor of aviation fuel. The mechanism in the high-quality utilization of all components of the aqueous phase bio-oil fraction was explored, which was favorable for the synthesis of biomass-based aviation fuel.
研究领域:
化学工程
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可再生能源
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生物质转化
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产品关联
DOI
高影响因子
Nature Communications
·
2021
·Vol. 12
·期 1
·1-12
·
IF 14.919
Xie Chao,Lin Longfei,Huang Liang,Wang Zixin,Jiang Zhiwei,Zhang Zehui,Han Buxing
Selective cleavage of C-C bonds is very important in organic chemistry, but remains challenging because of their inert chemical nature. Herein, we report that Zn/NC-X catalysts, in which Zn 2+ coordinate with N species on microporous N-doped carbon (NC) and X denotes the pyrolysis temperature, can effectively catalyze aerobic oxidative cleavage of C(CO)-C bonds and quantitatively convert acetophenone to methyl benzoate with a yield of 99% at 100 °C. The Zn/NC-950 can be applied for a wide scope of acetophenone derivatives as well as more challenging alkyl ketones. Detail mechanistic investigations reveal that the catalytic performance of Zn/NC-950 can be attributed to the coordination between Zn 2+ and N species to change the electronic state of the metal, synergetic effect of the Zn single sites with their surrounding N atoms, as well as the microporous structure with the high surface area and structural defects of the NC.
研究领域:
有机化学
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催化材料科学
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 7
·3988-3994
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IF 7.443
Xiang Li,Fangyuan Gai,Buyuan Guan,Ye Zhang,Yunling Liu,Qisheng Huo
Fe@C core–shell particles were successfully synthesized by coating Fe2O3 particles with resorcinol–formaldehyde resins (RFs) and then calcining to make the RFs carbonize, and at the same time to reduce the core to Fe. Furthermore, we designed and synthesized Fe@C yolk–shell particles to increase the number of active sites on the Fe surface. Compared with pure Fe material, the Fe in these particles possesses a high surface area without serious aggregation. Tests to remove 4-chlorophenol suggest that both these kinds of particles can degrade chlorophenol rapidly and thoroughly based on a Fenton-like reaction. Using Fe@C yolk–shell particles, the chlorophenol can be degraded to a concentration below the HPLC detection limit (<0.5 mg l−1) within 12 minutes. The magnetic properties and good stability of Fe@C endow it with promising potential for water treatment.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
Reaction Chemistry & Engineering
·
2024
·
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
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催化科学
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产品关联
DOI
高影响因子
ACS Catalysis
·
2017
·
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
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催化反应
✓ 已验证
DOI
高影响因子
ADVANCED SYNTHESIS & CATALYSIS
·
2017
·Vol. 359
·期 3
·454-466
·
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
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催化材料科学
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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
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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
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
·
航空航天工程
✓ 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）