INDUSTRIAL CROPS AND PRODUCTS
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2024
·
IF 5.6
Hongxi Zhang,Zhongke Li,Shuyu Tang,Xiande Yang,Meng li,Jing Yang,Liang Wei
This study examines the use of tetrabutylammonium tetrafluoroborate (TBABF 4 ) as a catalyst for the depolymerization of lignin and its model compound without the addition of oxidants. The impact of electrolytes, reaction times, and solvents on the cleavage of the α-O-4 bond in lignin is investigated. The experimental setup includes specific conditions such as the use of carbon cloth (CC) as the counter electrode and a platinum plate as the working electrode. The TBABF 4 catalyst effectively cleaved the α-O-4 bond in the lignin model molecule with notable selectivity and minimal formation of by-products, resulting in a substantial conversion rate of benzyl phenyl ether (95.7 %) and a high yield of benzaldehyde dimethyl aceta (92.4 %) under specific conditions. This investigation showcases a mild electrochemical catalytic depolymerization approach for lignin model molecules at ambient temperature, thereby presenting novel avenues for further exploration in the field.
研究领域:
化学工程
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可再生资源利用
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环境科学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Hongxi Zhang,Zhongke Li,Xiande Yang,Meng Li,Liang Wei,Jing Yang
Lignin is anticipated to serve as a replacement for dwindling fossil fuel resources owing to its abundant sources and renewable nature. The electrochemical oxidation technique for depolymerizing lignin has garnered significant interest for its environmentally friendly and mild operating conditions. Nevertheless, the current utilization of auxiliary electrolytes, predominantly organic bases, ionic liquids, and other specialized substances, poses a constraint on the widespread adoption of this approach. Furthermore, there is a scarcity of instances where electrochemical technology has been employed to depolymerize the α-O-4 bond in lignin for the production of highly selective acetals. In this study, a sodium chloride/methanol (NaCl/MeOH) system was utilized for the direct depolymerization of the α-O-4 bond in a lignin model molecule, specifically benzyl phenyl ether (BPE). The optimal conditions resulted in a 95.2 % conversion rate of the BPE substrate and a high yield of 94.5 % for the main product, benzaldehyde dimethyl acetal(Bda). This research offers a promising approach for the electrocatalytic depolymerization of α-O-4 bonds in lignin, leading to the selective production of acetal chemicals using a common auxiliary electrolyte at room temperature in just 2 h.
研究领域:
化学工程
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可再生资源技术
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产品关联
DOI
PubMed
高影响因子
GREEN CHEMISTRY
·
2024
·
IF 9.3
Qi Zhu,Bo Gong,Shuquan Huang,Yangxin Jin,Shengqin Liu,Shan Shao,Yuwei Yang,Taren Cataldo,Nicholas M. Bedford,Jason Chun-Ho Lam
The electrochemical selective oxidative transformation of lignin feedstocks into valuable oxygenated aromatics is essential to establish a sustainable biorefinery. In this study, we used a rhombohedral ZnIn2S4 (R-ZIS) electrocatalyst to realise the efficient anodic cleavage of C–O bonds in benzyl phenyl ether (BPE), an α-O-4 lignin model compound, to a series of industrially relevant oxygenated mono-aromatics. The reaction occurred at +2 VAg/AgCl, 65 °C, and atmospheric pressure. In optimised conditions, the reaction achieved over 99% conversion rate with a Faraday efficiency of 51.6% at 91.3% conversion of BPE, that is greater than most known electrocatalytic oxidative cleavage examples. The ZnIn2S4 electrocatalyst was deposited on a carbon cloth support, and its structural properties and surface morphology were extensively investigated. Systematic potential controlled electrolysis coupled with 18O isotopic labelling confirmed that C–O scission occurred exclusively between the benzylic carbon and phenolic oxygen. Furthermore, substrate competition studies were conducted to compare the electrocatalytic performance of the R-ZIS catalyst with that of its structural analogue, hexagonal ZnIn2S4, in terms of BPE and mono-aromatics conversion. The experimental results were supported by density functional theory calculations. The substrate scoping study revealed the suitability of the R-ZIS induced electrocatalytic system for a variety of substituted α-O-4/β-O-4 model dimers. Overall, this work demonstrates an efficient anodic process that can enable the atom-efficient valorisation of lignin to produce oxygenated aromatics. The proposed approach can complement the numerous existing reductive lignin cleavage methods.
研究领域:
化学工程
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可再生资源利用
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电化学催化
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DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2022
·
IF 4.598
Zhiwei Han,Haomin Jiang,Aiguo Xue,Gaoguo Ni,Yanzhi Sun,Yang Tang,Pingyu Wan,Yongmei Chen
Lignin valorization to obtain small aromatic compounds requires selective oxidation to break the linkage bonds among the C9 units in lignin molecules. It has been reported that hydrogen peroxide (H 2 O 2 ) generated through the oxygen reduction reaction (ORR) on the cathode could be an appropriate oxidizing reagent to depolymerize lignin, but the current efficiency was still unsatisfactory. In this study, a protic ionic liquid [Et 3 NH][HSO 4 ] is used as electrolyte instead of aqueous solution, and the generation rate of H 2 O 2 is determined as 0.0563 mmol cm −2 min −1 and the current efficiency of 79.7 % by the Ti-TPyP colorimetric method. Then using p -benzylethoxyphenol (PBP) as a lignin model compound, it is figured out that approximately-two molecules of H 2 O 2 are consumed for breaking one α-O-4 ether bond. Finally, in the electrolysis of an actual lignin sample, it is evaluated that about 19.4 molecules of H 2 O 2 are needed for producing one molecule of vanillin when taking vanillin as a representative degradation product of lignin.
研究领域:
化学工程
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生物化工
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产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
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2026
·Vol. 14
·期 3
·122374
·
IF 7.5
Feng Chen,Xiang Xia,Wei Chen,Wei Liu,Xinxin Liao,Lei Xiong,Yanqiao Jin
Refining lignin and its derivatives into biofuels and fine chemicals via catalytic transfer hydrogenation (CTH) has gained significant attention for its potential in utilizing renewable resources and reducing fossil fuel dependence. Herein, a series of bimetallic Cu-Co catalysts with varying metal ratios are synthesized via a facile hydrothermal method and successfully applied in the efficient CTH of the α-O−4 model compound benzyl phenyl ether (BPE) and corncob lignin. Cu 0.5 Co 1 @CN has the best performance among catalysts with different CuCo ratios due to the formation of the CuCo 2 O 4 phase which provides more acid sites and hydrogen adsorption/desorption sites. Under the reaction conditions of 190 °C in isopropanol, the Cu 0.5 Co 1 @CN catalyst achieves the complete conversion of BPE to cyclohexanol and toluene, and demonstrates excellent CTH performance towards other α-O−4 and β-O−4 model compounds. This catalyst simultaneously enables the demethoxylation and hydrogenation of phenolic compounds like guaiacol. Furthermore, Cu 0.5 Co 1 @CN efficiently converts corncob lignin, producing a high proportion of phenolic compounds in the resulting liquid (88.26%), while preventing the aromatic hydrocarbons from being hydrogenated. Overall, this work provides a novel and effective strategy for transforming lignin into high-value products.
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DOI
高影响因子
CHINESE CHEMICAL LETTERS
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2013
·Vol. 24
·期 12
·1091-1094
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IF 1.21
Xin-Ping Ouyang,Chun-Lei Liu,Yu-Xia Pang,Xue-Qing Qiu
A trimeric lignin model compound composed of α - O -4 and β - O -4 linkages was prepared by the microwave-assisted synthesis, which consisted of three steps: (a) the synthesis of 3-methoxy-4-benzyloxyacetophenone ( 2 ) from acetovanillone ( 1 ), (b) the bromination of compound 2 to produce 3-methoxy-4-benzyloxy- α -bromoacetophenone ( 3 ), and (c) followed by a nucleophilic substitution of compound ( 3 ) to obtain 3-methoxy-4-benzyloxy- α -(3-methoxy-4-(1-propenyl)phenol)-acetophenone ( 4 ). The target product was characterized by MS, 1 H NMR and 13 C NMR spectroscopy. It was found that the trimeric compound synthesized can be used as a preferable lignin model compound because it contains guaiacyl structural unit (3-methoxy-4-hydroxy phenyl propane) linked by α - O -4 and β - O -4 linkages. In addition, under the conditions of microwave irradiation, the reaction time of each step is significantly reduced, and the selectivity of target product is greatly improved. The yields of each step and the overall sequence are 95.31%, 87.3%, 90.6% and 75.4% (95.31% × 87.3% × 90.6%), respectively.
研究领域:
有机化学
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高分子化学
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绿色化学
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生物质转化
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DOI
高影响因子
BMC Chemistry
·
2019
·Vol. 13
·期 1
·1-15
·
IF 0
Guo J.,Ma Yu L.,Yu Jia Y.,Gao Yu J.,Ma Ning X.,Wu Xiao Y.
Herein, 2-(2-methoxyphenoxy)-1-phenylethanol (β- O -4), 2-methoxyphenyl anisole (α- O -4) and 4-phenoxyphenol (4- O -5) were selected as typical lignin model compounds. Given the effectiveness of traditional acid–base catalysts for lignin depolymerisation, a novel Ni/CaO–H-ZSM-5(60) catalyst was prepared to investigate the difficulty level of C–O bond of three model compounds cleavage in ethanol. It was observed that Ni/CaO–H-ZSM-5(60) had prominent performance on the C–O bond cleavage at very mild conditions (140 °C, 1 MPa H 2 ). Among them, the C–O bond of α- O -4 and β- O -4 could be completely cleaved within 60 min. Although the C–O bond of 4- O -5 had high bond energy, 41.2% of conversion was occurred in 60 min. The introduction of CaO could regulate the acidity of H-ZSM-5 to enhance the ability to break C–O bonds. Moreover, the possible pathways of C–O ether bonds in three lignin model compounds cleavage were proposed in order to selectively obtain target products from the raw lignin degradation.
研究领域:
化学工程
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催化科学
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DOI
RSC Advances
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2020
·Vol. 10
·期 71
·43599-43606
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IF 3.119
Xiaomeng Dou,Wenzhi Li,Chaofeng Zhu,Xiao Jiang,Hou-min Chang,Hasan Jameel
Efficient cleavage of aryl–ether linkages is a key strategy for generating aromatic chemicals and fuels from lignin. Currently, a popular method to depolymerize native/technical lignin employs a combination of Lewis acid and hydrogenation metal. However, a clear mechanistic understanding of the process is lacking. Thus, a more thorough understanding of the mechanism of lignin depolymerization in this system is essential. Herein, we propose a detailed mechanistic study conducted with lignin model compounds (LMC) via a synergistic Co–Zn/Off-Al H-beta catalyst that mirrors the hydrogenolysis process of lignin. The results suggest that the main reaction paths for the phenolic dimers exhibiting α-O-4 and β-O-4 ether linkages are the cleavage of aryl–ether linkages. Particularly, the conversion was readily completed using a Co–Zn/Off-Al H-beta catalyst, but 40% of α-O-4 was converted and β-O-4 did not react in the absence of a catalyst under the same conditions. In addition, it was found that the presence of hydroxyl groups on the side chain, commonly found in native lignin, greatly promotes the cleavage of aryl–ether linkages activated by Zn Lewis acid, which was attributed to the adsorption between Zn and the hydroxyl group. Followed by the cobalt catalyzed hydrogenation reaction, the phenolic dimers are degraded into monomers that maintain aromaticity.
研究领域:
化学工程
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催化
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有机化学
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木质素解聚
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产品关联
DOI
PubMed
高影响因子
FUEL PROCESSING TECHNOLOGY
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2021
·
IF 7.033
Xiangchen Kong,Chao Liu,Weicong Xu,Yue Han,Yuyang Fan,Ming Lei,Ming Li,Rui Xiao
Stubborn lignin (SL) is the thermochemically stable fragment generated from biomass utilization (e.g., pyrolysis , hydrolysis, fermentation, pulping), which is comparatively difficult to be further depolymerized into value-added bio-products. The cleavage of the stubborn linkages within the structure of SL, such as C C, α -O-4, and 4-O-5 linkages, is the key for its valorization. Herein, we investigated the depolymerization of SL through catalytic hydroprocessing in supercritical methanol with Cu/CuMgAlO x catalyst. The yield of monomers reached 37.76C% with 240 min at 300 °C. Cyclohexanols were identified as the major monomeric products, indicating the occurrence of hydrodeoxygenation and hydrogenation. GPC , quantitative 13 C NMR, HSQC NMR, and HMBC NMR analyses evidenced the depolymerization of SL and upgrading of its derivatives. Furthermore, the mechanistic studies were carried out to provide insights to the stubborn linkage cleavages. The degrees of difficulty to break up the three involved linkages obeyed the sequence of β -5 > 4-O-5 > α -O-4. The apparent activating energies ( E a ), chemisorption energies ( E c ), and bond dissociation energies (BDE) were determined computationally to support the experimental results from the perspectives of kinetics, chemisorption, and thermodynamics, respectively. This research provides a reliable way for the utilization of SL.
研究领域:
化学工程
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催化
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生物化学
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可再生能源
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）