ACS Catalysis
·
2018
·
IF 11.384
Wenjing Song,Shijie Zhou,Shihua Hu,Weikun Lai,Yixin Lian,Jianqiang Wang,Weimin Yang,Meiyu Wang,Peng Wang,Xingmao Jiang
We propose a surface atom engineering strategy to obtain a well-dispersed Co-incorporated MoS2 nanomaterial, which maximizes the Co–Mo–S phase and achieves high activity in hydrodeoxygenation (HDO) of lignin-derived phenolic compounds. It was shown by X-ray diffraction, transmission electron microscopy, Ramanspectroscopy, high-sensitivity low-energy ion scattering, and X-ray photoelectron spectroscopy that plenty of accessible Co–Mo–S phase were generated on the catalyst surface, which could accelerate the hydrodeoxygenation (HDO) reaction. Notably, most of the Co–Mo–S phases were located at the top surface of MoS2, which explained the full deoxygenation performance of the CoMoS catalyst. Moreover, among the diverse lignin-derived oxygenated compounds, phenolic hydroxyl HDO was structure-sensitive relative to diphenyl ether over Co-doped MoS2 catalysts. Effective conversion of mixed phenols to corresponding arenes such as BTX (benzene, toluene, and xylene) with high yield (>85%) and stable recyclability was exhibited by using the CoMoS catalyst with highly dispersed Co–Mo–S phase.
✓ 已验证
产品关联
DOI
高影响因子
Royal Society Open Science
·
2019
·Vol. 6
·期 2
·
IF 2.515
Lisheng Shi,Jiayan Ge,Shuangxi Nie,Chengrong Qin,Shuangquan Yao
Adsorbable organic halogens (AOX) are formed in pulp bleaching as a result of the reaction of residual lignin with chlorine dioxide. The natural structure of lignin is very complex and it tends to be damaged by various extraction methods. All the factors can affect the study about the mechanism of AOX formation in the reaction of lignin with chlorine dioxide. Lignin model compounds, with certain structures, can be used to study the role of different lignin structures on AOX formation. The effect of lignin structure on AOX formation was determined by reacting phenolic and non-phenolic lignin model compound with a chlorine dioxide solution. Vanillyl alcohol (VA) and veratryl alcohol (VE) were selected for the phenolic and non-phenolic lignin model compound, respectively. The pattern consumption of lignin model compounds suggests that both VA and VE began reacting with chlorine dioxide within 10 min and then gradually steadied. The volume of AOX produced by VE was significantly higher than that produced by VA for a given initial lignin model compound concentration. In a solution containing a combination of VA and VE in chlorine dioxide, VE was the dominant producer of AOX. This result indicates that the non-phenolic lignin structure was more easily chlorinated, while the phenolic lignin structure was mainly oxidized. In addition, AOX content produced in the combined experiments exceeded the total content of the two separate experiments. It suggested that the combination of phenolic and non-phenolic lignin structure can promote AOX formation.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
·
2019
·
IF 6.669
Pan Jiang,Qiang Li,Ce Gao,Jie Lu,Yi Cheng,Shangru Zhai,Qingda An,Haisong Wang
Here we report a centrifugation-based fractionation methodology that was integrated with three types of organic solvents to fractionate industrial alkali lignin toward the fabrication of lignin microsphere. The Fourier-transform infrared spectroscopy (FT-IR) result showed that the chemical structure of lignin was not changed by solvent fractionation. Soluble lignin in each solvent had lower molecular weight, improved polydispersity index (PDI) and less impurities (S, N), while insoluble lignin had a high bio-char yield and can be utilized as potential carbon source for porous carbon nanosphere materials. In addition, well-shaped lignin microsphere with smooth or anisotropic surface can be prepared by selecting proper lignin fraction without any chemical modification. This work thus provides a new strategy for the derivation of lignin as raw materials for value-added products, which paved a new way to develop a green and sustainable bio-refining industry.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
GREEN CHEMISTRY
·
2019
·Vol. 21
·期 11
·3081-3090
·
IF 9.405
Lin Dong,Yu Xin,Xiaohui Liu,Yong Guo,Chih-Wen Pao,Jeng-Lung Chen,Yanqin Wang
Transformation of lignin into high value-added phenolics is of great significance but extremely challenging. Herein, we report a single-step process for the preparation of phenolics from both 2-methoxy-4-propylphenol (one of the major products derived from lignin) and lignin oil (lignin-derived monomers) over Au-based catalysts. In this process, the desired Ar–OH substituents can be maintained and phenolics can be obtained with high yields. The performance of the Au/Nb2O5 catalyst is compared with those of Au/TiO2, Au/Al2O3 and Au/ZrO2 and it is shown that Au/Nb2O5 has high activity, excellent stability and remarkable selectivity to phenolics, with the yields of phenolics reaching 84.2% for 2-methoxy-4-propylphenol and 66.7 wt% for lignin oil. The detailed studies reveal that the hydrodeoxygenation of 2-methoxy-4-propylphenol undergoes two-steps, i.e., hydrolysis to propylcatechol catalyzed by the acid sites of supports, and the hydrogenolysis of propylcatechol to propylphenol realized by the synergistic effect between Au and the supports. It is found that the high hydrodeoxygenation activity of Au/Nb2O5 depends on both the electron-rich Au nanoparticles and the Nb2O5 support with the efficient cleavage of the Caromatic–O linkage. This study provides a new catalytic system towards highly efficient and selective conversion of lignin oils to valuable phenolics.
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Wei Zhang,Pei Yang,Xinghui Li,Ziqi Zhu,Minzhi Chen,Xiaoyan Zhou
An alkali lignin/poly (vinyl alcohol) (lignin/PVA) composite nanofiber membrane was fabricated by electrospinning and tested as an adsorbent for efficient Safranine T (ST) adsorption. Effect of lignin/PVA ratios on the morphology and chemical properties of the prepared composite membranes were studied. The influence of initial dye pH, time and temperature on the adsorption performance of composite membranes were investigated, and further evaluated the desorption and recycling behavior. The results showed that strong intermolecular hydrogen bonds were formed between the hydroxyl groups of PVA and lignin. The diameter of fiber displayed decreasing tendency to the increase in lignin content and the carbonization process. The excellent bead-free membranes were produced with the lignin content as high as 50 wt%. Further study found that the adsorption capacity increased with increasing the initial dye pH and temperature. The results of adsorption indicated that the absorption behavior of composite membranes was better consistent with the Langmuir isotherm and pseudo-second-order kinetic models. The adsorbent exhibited the excellent desorption behavior with an optimal desorption time of 4 h and constant recycling performance. Overall, these results indicate that lignin/PVA composite nanofiber membrane can be applied as a cost-efficient absorbent for removal of dyes from wastewater.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysts
·
2018
·Vol. 8
·期 2
·82
·
IF 3.465
Yadong Bi,Xiaojuan Lei,Guihua Xu,Hui Chen,Jianli Hu
The hierarchical HZSM-5 and Hβ zeolites were prepared by alkaline post-treatment methods adopting Na2CO3, TMAOH/NaOH mixture, and NaOH as desilication sources, respectively. More mesopores are produced over two kinds of zeolites, while the micropores portion is well preserved. The mesopores formed in hierarchical Hβ zeolites were directly related to the basicity of the alkaline solution, indicating that Hβ zeolite is more sensitive to the alkaline post-treatment. The hierarchical HZSM-5 and Hβ zeolites are more active than the parent one for catalytic fast pyrolysis (CFP) of Kraft lignin. Hierarchical zeolites retained the function of acid catalysis, while additionally creating larger mesopores to ensure the entry of bulkier reactant molecules. The increase of the condensable volatiles yield can be attributed to the improvement of the mass transfer performance, which correlates well with the change of mesoporous surface area. In particular, the condensable volatiles yield for the optimized hierarchical Hβ reached approximately two times that of the parent Hβ zeolites. In contrast to the parent HZSM-5, the optimized hierarchical HZSM-5 zeolite significantly reduced the selectivity of oxygenates from 27.2% to 3.3%.Keywords:catalytic fast pyrolysis;Kraft lignin;hierarchical zeolites;HZSM-5;Hβ
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2018
·
IF 3.024
Da Wang,Yuyang Wang,Xiaoyu Li,Lei Chen,Guangci Li,Xuebing Li
In situ catalytic hydrogenolysis of lignin is an efficient method for lignin valorization. Herein, a novel in situ lignin catalytic hydrogenolysis technique in alkaline aqueous solution over a NiAl alloy catalyst under mild conditions was systematically suited. Ni served as the active phase and could be exposed by etching Al atoms with alkaline aqueous solution. Meanwhile, H2 resources could be in situ generated and easily arrived at the adjacent exposed Ni sites to be activated. The in situ lignin hydrogenolysis system exhibits attractive depolymerization results under mild conditions, with an 86.8% conversion degree and 18.9 wt % yield of aromatic monomers at 220 °C, much higher than the traditional hydrogenolysis method using a commercial Raney Ni catalyst under high pressure external H2. The mechanism studies with lignin model compounds suggest that alkaline aqueous solution could promote the cleavage of C–O–C bonds and hinder the hydrogenation of the benzene ring. In addition, a moderate amount of exposed Ni sites as well as rich active hydrogen species are determinant for efficient lignin depolymerization.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2018
·
IF 3.412
Yuanyuan Li,Dongjie Yang,Shuo Lu,Sulin Lao,Xueqing Qiu
Alkali lignin (AL), an anionic polymer, is a byproduct of the paper industry. AL was first modified by quaternization to synthesize quaternized alkali lignin (QAL). The aim of the present study is to reveal the effects of sodium dodecyl benzenesulfonate (SDBS) on the microstructure of QAL. The interaction between SDBS and QAL is studied by means of zeta potential, fluorescence spectrophotometer, and static contact angle measurement. The results indicated that there is an electrostatic interaction and a hydrophobic interaction between QAL and SDBS. The SDBS/QAL complex can self-assemble into lignin-based colloidal spheres (LCSs) in an ethanol/water mixture, which have remarkable avermectin (AVM) encapsulation efficiency and antiphotolysis performance. The cumulative release amount of AVM encapsulated by LCS (LCS@AVM) after 72 h was 77%, and the release was still going on. The release behaviors of LCS@AVM can be controlled by adjusting the ratio (w/w) of LCS to AVM. More than 85% of AVM could be preserved even after 96 h of UV irradiation. LCS showed controlled release and UV-blocking performance for AVM.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2018
·Vol. 6
·期 21
·9971-9983
·
IF 9.931
Enmin Zong,Guobo Huang,Xiaohuan Liu,Weiwei Lei,Shengtao Jiang,Zhongqing Ma,Jifu Wang,Pingan Song
The design of an environmentally benign cost-effective adsorbent for superfast removal of phosphate from wastewater is vital but remains a huge challenge. Herein, we have developed a recyclable, low-cost nanostructured bio-adsorbent, poly(ethyleneimine)-graft-alkali lignin loaded with nanoscale lanthanum hydroxide (AL–PEI–La), by a facile fabrication. AL–PEI–La was found to exhibit an excellent adsorption performance toward phosphate ions. For example, 94% of the phosphate ions from 40 mL of a solution containing 50 mg P L−1 phosphate ions was removed in 60 min. Additionally, in a low phosphate concentration wastewater of 2.0 mg P L−1, 95% of phosphate was removed in just 1 min and 99% of phosphate was removed in 15 min and the phosphate concentration dramatically decreased below 50 μg P L−1, which met the standard of eutrophication prevention. The adsorption capacity of AL–PEI–La for phosphate ions was found to be 65.79 mg P g−1, which is 33 times larger than that of lignin. AL–PEI–La shows strong anti-jamming capability in terms of pH value (3.0–9.0) and the co-existing ions of the aqueous solution exhibiting highly selective capacity for phosphate removal. The interactions between surface precipitation and ligand exchange are predominantly responsible for the adsorption process. Importantly, it shows a good reusability and 85.76% of the original adsorption capacity remains after 3 cycles. Thus, the as-designed nanostructured bio-adsorbent with exceptional adsorption effectiveness and efficiency is expected to find extensive applications for remediating the phosphate-contaminated waters.
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2018
·
IF 3.849
Gaofeng Zhao,Xiaole Liu,Shixue Ren,Wenying Tan,Guizhen Fang
The high value utilization of lignin is attracting increased attention because of environmental problems and resource depletion. Although these are numerous reports describing the modification and degradation of enzymatic hydrolysis lignin (EHL), quantitative characterization is lacking. In this work, EHL was efficiently degraded using H 3 PW 12 O 40 /ZrO 2 (HPW/ZrO 2 ) as catalyst. Following degradation, the total hydroxyl group content and phenolic hydroxyl group content, measured by acid-base titration and ultraviolet spectrophotometry, were increased by 259% and 152%, respectively. Hansen solubility parameters were calculated using the specific retention time of probe solvents, measured by inverse gas chromatography (IGC), quantitatively characterizing changes in surface properties.
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Guanhua Wang,Xiaoqian Liu,Bo Yang,Chuanling Si,Ashak Mahmud Parvez,Jinmyung Jang,Yonghao Ni
Lignin heterogeneity, involving complex structure and high polydispersity, is a key challenge that restricts its value-added applications. Fractionation of heterogeneous lignin into several homogeneous subdivisions is an attractive and practical strategy to overcome this limitation. In this work, γ-valerolactone (GVL), a sugar-derived product, was used as a green solvent for lignin fractionation when mixed with water. The enzymatic hydrolysis lignin (EHL) was subdivided into three different fractions (F1, F2, and F3) by dissolving it completely in 60% aqueous GVL and then following gradient precipitation in 40%, 30%, and 5% aqueous GVL solutions, sequentially. Detailed characterization techniques were conducted to provide a comprehensive evaluation of the three obtained lignin fractions. Moreover, the proposed fractionation mechanism was further investigated on the basis of Kamlet–Taft parameters. The gel permeation chromatography (GPC) analyses showed that the three fractions presented lower polydispersity than the parent EHL and, furthermore, a gradual decreasing molecular weight due to the different solubility of various molecular weight lignins in aqueous GVL solvents. The structural analyses revealed that with the decrease of molecular weight, the guaiacyl unit content in lignin fractions decreased, with significant increases of functional groups (i.e., aromatic/aliphatic hydroxyl and carboxyl groups). The solvent recycling study showed that the aqueous GVL had a high recovery, and the recycled GVL had the same lignin fractionation performance as fresh GVL. Overall, compared with traditional fractionation using multiple organic solvents, the present work provides a green and efficient route to fractionate lignin and, therefore, significantly decreases its molecular weight polydispersity and structural heterogeneity.
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2018
·Vol. 10
·期 10
·1109
·
IF 2.935
Pan Jiang,Yi Cheng,Sheng Yu,Jie Lu,Haisong Wang
A protocol for the fractionation of lignin with 1-butanol as solvent has been proposed in order to improve the utilization of industry alkali lignin. 1-butanol soluble lignin (BSL) was used as a building block for temperature-sensitive hydrogel withN-isopropylacrylamide (NIPAAm) through graft polymerization. The result shows that 1-butanol fractionation is an effective method to improve the molecular weight homogeneity of lignin (PDI, 2.5 to 1.83) and increase the hydroxyl group content (0.585–1.793 mmol/g). The incorporation of BSL into the temperature-sensitive hydrogel can enhance the thermal stability and increase the hydrophobicity of the gel, which leads to a decrease in lower critical solution temperature (LCST). In addition, the compression strength, swelling ratio, and pore size of the gel can be adjusted by the dosage of lignin. This stimuli-responsive gel, with an LCST around 32 °C, is expected to be applied in the agricultural field as a pesticide carrier by stimulating release and absorption properties based on the change in natural environmental temperature.Keywords:1-butanol;fractionation;industrial alkali lignin;temperature-sensitive gel
✓ 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）