ACS Sustainable Chemistry & Engineering
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2021
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IF 8.198
Xiangchen Kong,Chao Liu,Ming Lei,Feng Gong,Yue Han,Yuyang Fan,Ming Li,Rui Xiao
The fundamental understanding of the catalytic performance of copper-based catalysts for lignin hydroconversion is delayed compared with the empirical optimization of the catalyst preparation. Herein, we investigate the interplay between the lignin-abundant oxygen-containing functional groups and Cu active species via the catalytic β-O-4 lignin linkage hydrogenolysis. Catalyst performance data and elemental spectra characterizing the catalyst demonstrate the dominance of Cu0 in the catalysis. Remarkably, Cα–OH and Cα═O in the aliphatic chain play critical roles in this process, without which the linkage cannot be broken. These groups markedly accelerate the linkage cleavage by decreasing both the chemisorption energy between Cβ–O and Cu0 and the bond dissociation energy of the linkage. On the contrary, the methoxyl groups attached to the aromatic rings hinder the bond cleavage as a result of the steric effect. Such hindrance is significantly affected by the amount and position of the methoxyl groups. The results of this work highlight the importance of the unique structures of lignin in its reductive depolymerization catalyzed by copper-based catalysts, which appear to offer an opportunity for tailoring efficient copper-based catalysts for lignin hydrogenolysis.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2021
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IF 5.279
Fei Li,Honglu Zhao,Ruijian Shao,Xiaoyu Zhang,Hongbo Yu
The Fenton reaction is considered to be of great significance in the initial attack of lignocellulose in wood-decaying fungi. Quinone redox cycling is the main way to induce the Fenton reaction in fungi. We show that lytic polysaccharide monooxygenases (LPMOs), through LPMO-catalyzed oxidation of hydroquinone, can efficiently cooperate with glucose dehydrogenase (GDH) to achieve quinone redox cycling. The LPMO/GDH system can enhance Fe3+-reducing activity, H2O2 production, and hydroxyl radical generation, resulting in a fueled Fenton reaction. The system-generated hydroxyl radicals exhibited a strong capacity to decolorize different synthetic dyes and degrade lignin. Our results reveal a potentially critical connection between LPMOs and the Fenton reaction, suggesting that LPMOs could be involved in xenobiotic compound and lignin degradation in fungi. This new role of LPMOs may be exploited for application in biorefineries.
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PubMed
高影响因子
Molecular Catalysis
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2021
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IF 5.062
Changcheng Shen,Wenzhi Li,Baikai Zhang,Fengyang Xue,Xiaomeng Dou,Xia Zhang,Yihang Jiang
Lignin, which represents the most abundant renewable aromatic biomass resource on the earth, is promising as an alternative for the production of chemicals. We presented a modified method that provides the hydrogen source in the reaction with a mixed solvent of alcohol, acid and water, replacing the original method that directly provides a hydrogen source with external hydrogen. In addition, a new cobalt supported on nitrogen doped carbon catalyst preparation method (one-pot) was presented. We proposed one-step method in which corn stover lignin is converted to target monomers over Co/AC-N_one-pot catalyst and mixed solvent. The role of the alcohol to acid and water mixed solvent not only extract lignin fragments from the matrix but also provide the hydrogen source. Cobalt which has electronic interaction with the nitrogen reformed alcohols to obtain hydrogen and stabilized lignin intermediates during the reaction by hydrogenation of active bonds. Different kinds of nitrogen including pyridinic and pyrrolic nitrogen functional groups plays a critical role in stabilizing Co. Nearly complete delignification (91%) and high yield of target monomers (23.8%) can be obtained under the conditions (5wt% Co/Ac-N_one-pot, 10:1:1mixture solvent consist of isopropanol/water/ formic acid , 235 °C, 200 min, 0.1 MPa N 2 ), and the selectivity of target monomers was 85%. Circulation experiment of catalyst was performed directly without any operation of the residue, and it could maintain 90% activity in the first four cycles.
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APPLIED SURFACE SCIENCE
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2021
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IF 6.707
Lingli Zhu,Dekui Shen,Qian Liu,Chunfei Wu,Sai Gu
Biomass transformation into high-value carbon nanomaterials plays a dual role of easing the energy material crisis and reasonable disposal of waste. Here, we employed biomass lignin as carbon source to synthesize fluorescent carbon quantum dots (CQDs) through a facile two-step method. The preparation condition is optimized at 0.3 g of acid additive and 200 ℃, 16 h of hydrothermal treatment. The resultant CQDs with the average diameter of 4.86 nm and high quantum yield of 23.68% are composed of carbon cores and surface functional groups, exhibiting the maximum green emission wavelength of 476 nm. The formation mechanism involves acid dissociation of lignin in the first step, and then the aromatic refusion of lignin fragments. The CQDs show great advantages as fluorescent nanoprobe for metal ion detection, which present an apparent and selective fluorescence quenching effect on Fe 3+ . This CQD nanoprobe has a highly sensitive response to Fe 3+ ions in the concentration of 0 ~ 300 μM with detection limit of 0.77 μM. The utilization of renewable biomass lignin in this study not only opens the avenue of the sustainable, cost-effective and mass production of CQDs, but also provides a novel alternative nanoprobe for sensing field.
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Journal of Environmental Chemical Engineering
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2021
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IF 5.909
Bin Yan,Xiaoyu Wang,Xiaoling Zhang,Shengqu Liu,Min Li,Rong Ran
Chemical dispersants are a controversial solution for oil spill remediation, and the potential toxicity of chemical surfactants to the marine ecology has prompted much research for eco-friendly dispersants with superior dispersing ability. Herein, an efficient Pickering emulsifier was prepared on the basis of the synergistic effect of sulfonated lignin (SL) and nickel hydroxide (Ni(OH) 2 ) micron particles. The interaction of SL and Ni(OH) 2 particles was characterized by the contact angle, shear viscosity and Zeta potential measurements. Confocal fluorescence microscopy and optical microscopy images revealed the oil droplet structure. The average emulsion droplet size and emulsification index were investigated. These results indicate that the addition of SL has a synergistic stabilizing effect in high salinity seawater. Here, Ni(OH) 2 particles alone are not an efficient emulsifier in seawater because of the strong flocculation caused by high salinity. The adsorption of Ni(OH) 2 particles by SL changed their contact angle and benefitted their adsorption at the oil-seawater interface, providing a solid barrier to avoid droplet coalescence, and the stable O/W emulsion exhibited great stability, smaller droplet size and larger oil-water interface area, which facilitated the subsequent natural degradation of crude oil. Therefore, this may be an environmentally friendly and harmless new method for SL and Ni(OH) 2 particles to deal with marine oil spill problems.
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Journal of Environmental Chemical Engineering
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2021
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IF 5.909
Lang Gong,Hongye Wu,Xiangyi Shan,Zhili Li
The development of low-cost, high-efficienct, and environmentally benign adsorbents for the removal of antibiotics and heavy metal ions in water is greatly needed. Phosphorylated alkali lignin (PAL) microparticles were newly fabricated via a facile one-pot method. The characterization confirmed that the phosphate group was successfully introduced into the lignin matrix, and the specific surface area of the obtained PAL was 9.53 m 2 ·g -1 , 5.6 times that of lignin (1.71 m 2 ·g -1 ). The adsorption behavior of PAL was initially investigated in a batch mode by using levofloxacin hydrochloride (LH) as a model. PAL performance was then validated to other contaminants as Pb(II), tetracycline (TC), and sulfadiazine (SA). The results indicated that 99.91% of LH ( C 0 =80 mg·L -1 ) could be removed by PAL (0.02 g/50 mL) within 80 min. The adsorption capacity of PAL to LH and Pb(II) reached 389.1 mg·g -1 and 349.2 mg·g -1 , respectively, better than earlier adsorbents. Importantly, PAL had a strong ability to remove the complex pollutants with coexisted Pb(II) and LH in water and was also applicable for adsorption of TC and SA. XPS and FTIR results show that the adsorption is mainly related to π-π stacking, hydrogen bonds and electrostatic interaction. The adsorption amount of LH in fixed-bed column was 240.5 mg·g -1 and removal percentage of LH and Pb 2+ in real wastewater was above 90% and 70% which indicated the great application potential.
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高影响因子
MOLECULES
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2021
·Vol. 26
·期 19
·5740
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IF 4.412
Kai Zhang,Yanchao Liu,Sheng Cui,Yimin Xie
To elucidate the chemical linkages between lignin and carbohydrates in ginkgo cell walls,13C-2H-enriched cell wall-dehydrogenation polymers (CW-DHP) were selectively prepared with cambial tissue fromGinkgo bilobaL. by feeding D-glucose-[6-2H2], coniferin-[α-13C], and phenylalanine ammonia-lyase (PAL) inhibitor. The abundant detection of13C and2H confirmed that D-glucose-[6-2H2] and coniferin-[α-13C] were involved in the normal metabolism of ginkgo cambial cells that had been effectively labelled with dual isotopes. In the ginkgo CW-DHP, ketal and ether linkages were formed between the C-α of lignin side chains and carbohydrates, as revealed by solid state CP/MAS13C-NMR differential spectroscopy. Furthermore, the DMSO/TBAH ionic liquids system was used to fractionate the ball-milled CW-DHP into three lignin-carbohydrate complex (LCC) fractions: glucan–lignin complex (GL), glucomannan–lignin complex (GML), and xylan–lignin complex (XL). The XRD determination indicated that the cellulose type I of the GL was converted into cellulose type II during the separation process. The molecular weight was in the order of Ac-GL > Ac-GML > XL. The13C-NMR and1H-NMR differential spectroscopy of13C-2H-enriched GL fraction indicated that lignin was linked with cellulose C-6 by benzyl ether linkages. It was also found that there were benzyl ether linkages between the lignin side chain C-α and glucomannan C-6 in the13C-2H-enriched GML fraction. The formation of ketal linkages between the C-α of lignin and xylan was confirmed in the13C-2H-enriched XL fraction.Keywords:lignin–carbohydrate complexes;CW-DHP;isotope labelling;ginkgo;NMR
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高影响因子
INDUSTRIAL CROPS AND PRODUCTS
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2021
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IF 5.645
Junxian Xie,Jun Xu,Zheng Cheng,Shiyun Zhu,Bin Wang
In this study, the eco-friendly heteropoly acids-phosphotungstic acid (PTA) was chosen as a catalyst to assist neutral deep eutectic solvents (DESs) for deconstructing corn straw. The reactions were performed with a shorter time at 110–150 °C than other DES system. The results revealed that most of the lignin (86.1 %) and hemicellulose (89.7 %) were removed while cellulose was obtained in high yields (88.9–94.3 %). Benefiting from the removal of hemicellulose and lignin, the enzymatic digestibility of pretreated materials was noticeably boosted to 94.4 %, which was 5.3-fold higher than the untreated corn straw. Meanwhile, the regenerated lignin nanoparticle was acquired with a relatively high purity (more than 85 wt%), low and homogeneous molecular weight (5669−2437 g/mol). Furthermore, the PTA/DES demonstrated excellent cycle performance. Overall, technically feasible PTA catalyzed DES pretreatment presented in-depth analysis for effective deconstruction of corn straw recalcitrance for crops valorization in the future.
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FUEL
·
2019
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IF 5.128
Wenjing Song,Weikun Lai,Yixin Lian,Xingmao Jiang,Weimin Yang
Catalytic transformation of lignin is a sustainable way to provide aromatics, which depends on the structure and property of catalytic sites. A bifunctional sulfated ZrO 2 supported CoMo sulfide catalyst has been synthesized by in situ exsolution approach. The exsolved CoMo-sZr(exs) catalyst significantly enhanced the initial C–O bond cleavage rate (0.058 mol·g −1 ·h −1 ) compared to the impregnated and physically mixed sulfated ZrO 2 supported CoMo sulfide catalysts. Notably, the reusability tests also showed that the as-prepared catalyst presented total ethers conversion of 94% with aromatics yield of 86% after four consecutive cycles. This was related to the appropriate sulfide-support interaction, acid sites and highly-dispersed CoMo sulfide, in conformity with the catalyst characterization. Thereby it could facilitate reactant adsorption and effectively break down the C–O bonds in lignin derived fragments to form aromatics. This work points out a new avenue for the design of effective bifunctional catalysts for lignin depolymerization.
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高影响因子
APPLIED SURFACE SCIENCE
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2019
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IF 5.155
Shan Wang,Zhuorong Hu,Jun Shi,Guokang Chen,Qian Zhang,Zengsheng Weng,Kun Wu,Mangeng Lu
In this work, the lignin, undervalued sustainable biomaterials, was modified and utilized to produce low-defect graphene from pristine graphite by exfoliation in water. The non-covalently interactions between modified lignin (lignin-OH) and graphene were confirmed to improve the dispersion and stability of the nanocomposites. As an additive, the lignin-OH/graphene dispersion was added into waterborne epoxy resin to enhance anti-corrosion of the nanocomposites. By the analysis of the electrochemical impedance spectroscopy (EIS), the nanocomposite coatings displayed higher impedance value at low frequency and bigger phase angle at high frequency with respect to the pure epoxy coatings. By fitting with equivalent circuits, the coating resistance (R c ) and charge-transfer resistance (R ct ) of 0.5% lignin-OH/graphene/WEP coatings are one or two orders of magnitude higher than that of pure epoxy coatings. The better anticorrosion effect should be attributed to well-dispersed graphene with the assistance of lignin-OH which generated the “labyrinth effect” of corrosive route. Therefore, this work provides a new way to enhance anticorrosive ability of waterborne epoxy resin, and it also gives a noteworthy strategy for development of biomaterial lignin's high value-added applications.
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高影响因子
APPLIED ENERGY
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2019
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IF 8.426
Haowei Li,Hongwei Ma,Weijie Zhao,Xuehui Li,Jinxing Long
Biofuel production from renewable resources is becoming an increasingly attractive option given the depletion of fossil fuels and the environmental problems caused by the excessive use of unsustainable energy resources. In this study, an efficient approach is provided for high-quality oxygen-containing fuel production from renewable lignin bio-oil. The results demonstrate that the calcination temperature has a remarkable effect on the catalyst structure, surface Ni content and physico-chemical properties of the Ni/MgO material, all of which result in significantly different performances in the upgrading of lignin bio-oil. At 160 °C for 4 h and 3 MPa of hydrogen, a 98% lignin bio-oil model compound of guaiacol is converted with 97% cyclohexanol selectivity in the presence of 15% Ni/MgO-850. Furthermore, the optimized catalytic system is reusable and shows good catalytic performance in the upgrading of both light and heavy lignin bio-oils, indicating that it is a promising strategy for renewable lignocellulosic biomass valorization.
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CATALYSIS TODAY
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2014
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IF 3.309
Cong Zhang,Jing Xing,Liang Song,Hongchuan Xin,Sen Lin,Lishu Xing,Xuebing Li
Aqueous phase catalytic upgrading of phenolic monomers to hydrocarbons have been explored using Pd/C combined with HZSM-5 zeolite catalysts in the presence of H 2 . 2-Methoxyl-4-allylphenol (eugenol), which consists of methyl ether bond, hydroxyl group, aromatic ring and propyl olefin bond, was chosen as a classic lignin model compound. This research focuses on the relationship between the acidity of zeolites and the deoxygenation activities basis on the hydrodeoxygenation (HDO) of eugenol. The results indicated that the decrease of Si/Al ratio resulted in the increase of the acidity of the zeolites, which significantly influenced their catalytic performance for product distributions. Over the HZSM-5 (Si/Al = 12.5) catalyst, the 2-methoxyl-4-propylphenol conversion of 86.5% and the hydrocarbon selectivity of 73.4% were obtained with the HDO of eugenol under 513 K and 5 MPa hydrogen pressure. Owing to the lower selectivity of hydrocarbon with HZSM-5 (Si/Al = 50) as acidic catalyst, the pore treatment was used to enlarge the outer surface of zeolite. After modified by alkali-treatment, much more acid active sites were provided for feasible accessibility of oxygenated reactants. The selectivity of hydrocarbons was improved by the alkaline treatment of HZSM-5 zeolite with 0.3 mol L −1 sodium hydroxide solution.
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