MOLECULES
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2020
·Vol. 25
·期 9
·2109
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IF 3.267
Changzhou Chen,Peng Liu,Haihong Xia,Minghao Zhou,Jiaping Zhao,Brajendra K. Sharma,Jianchun Jiang
It is of great importance to explore the selective hydrogenolysis of β-O-4 linkages, which account for 45–60% of all linkages in native lignin, to produce valued-added chemicals and fuels from biomass employing UV light as catalyst. TiO2exhibited satisfactory catalytic performances in various photochemical reactions, due to its versatile advantages involving high catalytic activity, low cost and non-toxicity. In this work, 20 wt.% Ni/TiO2and oxidant PCC (Pyridinium chlorochromate) were employed to promote the cleavage of β-O-4 alcohol to obtain high value chemicals under UV irradiation at room temperature. The Ni/TiO2photocatalyst can be magnetically recovered and efficiently reused in the following four consecutive recycling tests in the cleavage of β-O-4 ether bond in lignin. Mechanism studies suggested that the oxidation of β-O-4 alcohol to β-O-4 ketone by oxidant PCC first occurred during the reaction, and was followed by the photocatalysis of the obtained β-O-4 ketone to corresponding acetophenone and phenol derivates. Furthermore, the system was tested on a variety of lignin model substrates containing β-O-4 linkage for the generation of fragmentation products in good to excellent results.Keywords:lignin;β-O-4;photocatalyst;Ni/TiO2;oxidant PCC
研究领域:
化学工程
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环境科学
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DOI
PubMed
高影响因子
CATALYSIS LETTERS
·
2019
·Vol. 150
·期 6
·1591-1604
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IF 2.372
Du Boyu,Chen Changzhou,Sun Yang,Liu Bingyang,Yang Yingying,Gao Si,Zhang Zhenshu,Wang Xing,Zhou Jinghui
Abstract Catalytic depolymerization of lignin to produce bio-oil, liquid fuels, and aromatic chemicals in high yields is important for a biorefinery to remain competitive. In this study, undoped and Ni-doped catalysts for depolymerization of rice husk lignin (RHL) were developed and analyzed. The results showed that the catalysts had hydrotalcite-like structures with lamellar morphology. With suitable Ni-doping amount, the catalysts had high activity, thus better promoted the depolymerization of RHL. Among all catalysts, the Ni1/4MgAl catalyst could best promote the cleavage of the β-O-4 aryl ether bond in RHL molecule and thus could substantially increase the yields of bio-oil. The depolymerization catalyzed by this catalyst was also found to be temperature-, time-, and solvent-dependent. This study provides information that can be beneficial to the biorefinery industries and may help promote the valorization of lignin. Graphic Abstract
研究领域:
生物质能
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催化化学
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可再生资源
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DOI
高影响因子
RSC Advances
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2016
·Vol. 6
·期 22
·17880-17887
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IF 3.289
Guodian Zhu,Xinping Ouyang,Yun Yang,Tao Ruan,Xueqing Qiu
Lignin is an abundant renewable feedstock with a complicated and ill-defined structure. As β-O-4 aryl ether bonds are dominant among all the linkages in lignin, it is important to explore lignin depolymerization targeting the cleavage of the β-O-4 aryl ether bond for efficiently utilizing this biomass. Selective cleavage of chemical bonds in β-O-4 lignin model compounds was investigated by using Fe2(SO4)3, HZSM-5 and Pd/C as catalysts under microwave irradiation. When Fe2(SO4)3 or HZSM-5 was used as a catalyst, the Cα–Cβ bond of the C3 side chain in the model compound was broken to form aldehyde, secondary alcohol or ketone compounds. When Pd/C and formate were used as the catalyst, the β-O-4 aryl bond of the non-phenolic model compound was selectively cleaved and hydrogenation of CC on the side chain occurred at the same time. However, the hydrogenation reaction of CC on the side chain was faster than that of cleavage of the ether bond. Increasing Pd content favored the selective cleavage of the β-O-4 bond, and microwave irradiation accelerated the cleavage of the β-O-4 bond dramatically. At a high dosage of formate or high temperature, the condensation reaction among phenolic products was promoted due to the presence of an active phenolic hydroxyl group. The β-O-4 bond of the phenolic model compound was also selectively cleaved with Pd/C as the catalyst, and the reaction temperatures of cleaving about one half β-O-4 bonds of the non-phenolic and phenolic model compounds were 120 and 100 °C, respectively.
研究领域:
生物化学
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可再生资源利用
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DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2024
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IF 7.7
Xian-Sheng Cao,Xu-Liang Lin,Bo-Ya Li,Ru-Chun Wu,Lei Zhong
Deep eutectic solvents (DES) are promising green solvents for depolymerization and reconstruction of lignin. Revealing the transformations of lignin during DES treatment is beneficial for high potential lignin applications. In this study, bagasse lignin was treated with a binary DES and three ternary DESs, respectively. The results showed that net hydrogen bonding acidity(α-β) value of DES was positively correlated to the increment of phenolic hydroxyl of lignin, and the ternary DES of choline chloride-formic acid-oxalic acid (ChCl-FA-OA) exhibited the best phenolation performances. The phenolic hydroxyl content of ChCl-FA-OA treated lignin was increased by 50.4 %, reaching 2.41 mmol/g under optimum conditions (120 °C, 4 h, ChCl-FA-OA = 1:2:1). Moreover, it was found that the cleavage of β-O-4′ aryl ether bond and ester bond were dominant reactions during the treatment, accompanied by condensation reactions. Additionally, the obtained lignin oil contained various syringyl and guaiacyl derived phenolic compounds. Especially, the content of acetovanillone in lignin oil reached 29.94 %, much higher than in previous studies. Finally, the degradation mechanism of lignin in ChCl-FA-OA system was proposed. The present work provided insights into the relationship between lignin phenolation and DES properties. The novel ChCl-FA-OA system can achieve efficient lignin depolymerization, and convert lignin biomass into value-added chemical products.
研究领域:
化学工程
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材料科学
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生物技术
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绿色化学
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DOI
PubMed
高影响因子
FUEL
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2024
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IF 6.7
Zhuang Li,Zi-Chun Fan,Xiang Bai,Xian-Yong Wei,Yierxiati. Dilixiati,Qian-Qian Kong,Ji Zhao,Yong-Hui Feng,Jun-Long Wang,Xing Fan,Xiao-Yan He,Hai-Xu Zou,Zhi-Min Zong
MY zeolites with mesopores were prepared by hydrothermal method using functionalized SiO 2 (F-SiO 2 ) as a silica source, and hydrophobic bifunctional Ru/MY- O catalysts were obtained by deposition precipitation method and silylation treatment. This work aims at obtaining polycyclic alkane (PCA) based high-density hydrocarbon fuels (HDHFs). We focused on the catalytic hydroconversion (CHC) of 2-phenoxy-1-phenylethanol (PP-ol) and oxydibenzene (ODB), two typical lignin-related model compounds (LRMCs), over Ru/MY- O . The effects of different reaction conditions and catalysts on the product distribution in PP-ol and ODB were investigated. The partial hydrogenation of ODB was found to be a necessary step before achieving C-O ether bond cleavage and C-C bond coupling. The balance of metal/acidic sites is critical for maximizing PCA yields. Changes in the metal/acid ratio had a greater effect on PCA yield in PP-ol than in ODB. Poor stability of cycloalkyl cations and partial hydrogenation of ODB hinder the generation of C-C coupling products. The incorporation of mesopores and hydrophobic treatment were found to weaken the negative effects of C-C bond coupling products and water on the catalyst. The conversion of Ru 3 /MY- O was improved by nearly 10% compared to Ru 3 /Y in the fifth cycle reaction. This work provided a theoretical basis for the generation of HDHFs from lignin.
研究领域:
化学工程
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催化
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可再生能源
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材料科学
✓ 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）