FUEL
·
2024
·
IF 6.7
Xi Li,Haiyong Wang,Kingdom Alorku,Jin Wang,Longlong Ma,Ying Xu
Efficient hydrogenolysis of C-O bonds in lignin offers a promising pathway for producing high-value-added biofuels and chemicals. However, designing an easily synthesized, highly active catalyst for this process remains a challenge. In this paper, a series of Ni-M(Pd, Pt, Ru)/C catalysts were prepared and synergized with NaOH to produce aromatic compounds from β-O-4 model compound (MC). Among the catalyst systems, Ni-0.25 % Pd/C-NaOH completely converted β-O-4 MC at mild conditions (150 °C, 2 MPa H 2 , 3 h) to produce monomers with a yield of 95.6 wt% and excellent selectivity of the bond-breaking products as high as 85.5 %. Recycling tests showed that the Ni-0.25 % Pd/C catalyst remained stable after five cycles, with high activity and without the need for a further reduction before runs. Further, the catalytic system has proven to exhibit high activity for the cleavage of other types of lignin MC, such as 4-O-5, α-O-4, β-O-4 and ether bond (diphenyl ether, benzyl phenyl ether, Guaiacolylglycerol-β-guaiacol ether, benzyl ether) and also effective for lignin from enzymatic cleavage (LEC). Hydrogenolysis of LEC achieved a monomer yield of 34.5 wt%; the molecular weight (555 g/mol) of the hydrogenolysis oligomer was significantly reduced compared to LEC (2872 g/mol). The highly active and stable Ni-0.25 % Pd/C-NaOH catalytic system provides a promising pathway for the efficient hydrogenolysis of lignin and lignin model compounds to produce high-value biofuels and chemicals.
研究领域:
化学工程
·
可再生资源利用
✓ 已验证
DOI
高影响因子
RSC Advances
·
2013
·Vol. 3
·期 46
·24586-24592
·
IF 2.562
Junlong Song,Aijian He,Yongcan Jin,Qiang Cheng
A facile procedure to synthesize an amphoteric cellulose (AC) derivative in one pot using NaOH–urea solution as solvent was developed to avoid the time-consuming separation and purification between steps in conventional methods. Microcrystalline cellulose (MCC) was initially dissolved in 7 wt% NaOH–12 wt% urea aqueous solution at cold temperature and followed by reaction of 3-chloro-2-hydroxyl-propyltrimethyl ammonium chloride and 3-chloro-2-hydroxypropanesulfonic acid sodium salt sequentially or simultaneously at a designed temperature in one container. The degree of substitution (DS) values for positively and negatively charged groups were found to be a function of reaction temperature, dosages of cationic and anionic reagents, reaction time and the addition order of the two reagents. The total DS values of obtained ACs ranged between 0.046 and 0.76, all AC samples except AC-1 were soluble in water. The paper strength performance of ACs was tested and the results indicate that the strength improvement of AC products strongly relates to the DS of ACs. The product with DS of 0.69 can improve the tensile, tear and burst strength index of a paper sheet by about 20% compared with the control at a dosage of 1%.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2025
·
IF 12.5
Jinping Peng,Rongwei Fu,Yihui Huang,Jinqing Lu,Xiaofeng Xie,Zhenkun Xue,Mingjie Chen,Xingrou Wu,Hangbo Yue,Haiyan Mai
Alkaline aqueous solutions facilitate the rapid extraction of high-performance cellulose nanofiber (CNF) at 15 °C. However, the role and mechanism of NaOH in this process remain unclear. This study investigated the dissolution process of cellulose by controlling the NaOH concentration (1–7 wt%) at 15 °C and explored the effect and underlying mechanism of the NaOH concentration on cellulose dissolution in alkaline solvents. The results showed that the addition of NaOH strengthened the hydrogen bonding network of the solvent, whereas the addition of urea and thiourea promoted the dissolution of cellulose. The higher the concentration of NaOH is, the smaller the volume of hydrate molecules formed; smaller molecules more readily enter the cellulose molecules and form new hydrogen bonds with cellulose molecular chains, thereby destroying the original hydrogen bonds between cellulose molecules and their crystal structure. During dissolution, cellulose decomposes into microfibrils, and nanosized cellulose separates; moreover, the diameter and length of the CNF decrease with increasing NaOH concentration. When the concentration of NaOH reaches 7 %, the cellulose is completely broken down into CNF, and the yield is >60 %. As dissolution progresses, the crystallinity of cellulose first increases and then decreases (75.95 %–81.00 %–77.02 %), but its crystal size remains unchanged.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CATALYSIS LETTERS
·
2024
·Vol. 154
·期 8
·4756-4767
·
IF 2.3
Liu Kande,Wang Sitan,Zheng Lishan,Lou Shifeng,Meng Xuan,Cao Fahai,Liu Naiwang,Shi Li
The catalytic performance of Hβ zeolite treated with different concentration of NaOH on the alkylation of tert-butanol with phenol was studied. The effect of NaOH concentration on the crystallinity, morphology, textural property and acidity of Hβ zeolite was studied by X-ray diffraction (XRD), scanning electron microscope characterization (SEM), N 2 adsorption–desorption, Fourier transform infrared spectroscopy (FT-IR) and pyridine adsorption infrared spectra (Py-IR) techniques. A certain concentration of NaOH treatment can regulate the pore structure of Hβ zeolite and remove part of framework aluminum and framework silicon, thus achieving the purpose of regulating the pore structure and acidity of the catalyst. Though lower Bronsted to Lewis acid amount ratio when treated NaOH concentrations were 0.15 mol/L, leading to the increasing of selectivity to 4-TBP. The Hβ-0.2 M showed the high selectivity of 90.21% for synthesis of 4-tert-butyl-phenol (4-TBP), compared with the unmodified parent zeolite, the selectivity of 4-TBP improved 16.7%. Graphical Abstract
研究领域:
催化化学
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材料科学
✓ 已验证
DOI
高影响因子
CELLULOSE
·
2018
·Vol. 25
·期 12
·7211-7224
·
IF 3.809
Fu Feiya,Zhang Weilan,Zhang Ruihong,Liu Lin,Chen Shichang,Zhang Yupeng,Yang Binbin,Touhid Salvia,Liu Xiangdong,Zhou Jinping,Yao Juming
Abstract Cellulose hybrid fibers embedded with silver nanoparticles (Ag NPs) were prepared from a spinning dope through a bottom-up approach. Instead of using toxic agents or high temperature, an alkaline cellulose dope was directly used as a reducing agent for in situ synthesis of Ag NPs. The regenerated cellulose fibers displayed a dense circular microstructure and Ag NPs with a mean diameter of 40.1 nm were inlaid on its surface and inside. By increasing the spinning drawing ratio, the diameter and Ag content of the nanohybrid fibers decreased while its tensile strength in dry state increased significantly. Because of the embedded structure of NPs, the width of inhibition zone for the nanohybrid fibers against S. aureus and E. coli was small. However, both bacteria could be killed within 5 h in the presence of the nanobybrid fibers. In particular, the nanobybrid fibers showed excellent antibacterial durability and low cell toxicity. Besides, it was demonstrated that the nanobybrid fibers with lower diameter showed better catalytic activity and the catalytic efficiency could reach 99.3% for methyl orange. This biosynthesis approach is expected to offer a sustainable method for scale-up fabrication of functional cellulose fibers. Graphical abstract
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CONTAMINANT HYDROLOGY
·
2025
·
IF 4.4
Guofu Huang,Mianmian Wang,Changchun Li,Qianqian Wu,Qing Liu,Shasha Zhao,Yucui Shi,Haoran Cheng,Chenxi Zhang
The effective utilization of biomass waste for the fabrication of biochar adsorbents has aroused significant interest. In this work, a novel hierarchical porous biochar (HPBC) was successfully synthesized by dry mixing combined with one-step pyrolysis method using cucumber straw as a raw material and NaOH as an activator. The prepared HPBC was then applied to remove doxycycline (DOX) from aqueous solutions. HPBC comprised hierarchical porous structures with excellent specific surface area (1409.75 m 2 g −1 ), high pore volume (0.6549 cm 3 g −1 ), and small average pore diameter (1.8582 nm). HPBC was found to contain multiple functional groups involving hydroxyl, carbonyl, amine, and aromatic structure. The adsorption kinetics and isotherm of DOX on HPBC were well described by the Avrami fractional order model and Sips model, suggesting that the adsorption process involved multiple kinetics as well as monolayer and multilayer adsorptions. HPBC exhibited an excellent adsorption capacity for DOX with the maximum value of 552.30 mg g −1 at 25 °C (Sips model). The possible adsorption mechanisms of DOX on HPBC included pore filling, π-π interactions, hydrogen bonding, and electrostatic interactions. This study provided a new approach for resource utilization of straw waste and effective removal of antibiotics from water.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Chemical Engineering and Processing-Process Intensification
·
2023
·
IF 4.3
Yaping Zhang,Tongying Feng,Jingli Liu,Qingze Jiao,Bin Zhen
Glycerol is one cheap byproduct in production of biodiesel, and the ketalization of glycerol is one of the most important and effective way to increase its value and improve the sustainability of biodiesel. The ketalization of glycerol with acetone is always catalyzed by acid catalyst. In this work, NaOH was added into the reaction system during the ketalization process catalyzed by NaHSO 4 , and it was found for the first time that this process could be intensified by NaOH significantly. The acidity of acidic catalysts would affect their catalytic performance. Increasing reaction temperature and time, molar ratio of acetone to glycerol, the dosage of NaHSO 4 and molar ratio of NaOH to NaHSO 4 could favor for the ketalization, but the excessive formation of water and the evaporation of acetone would retard the reaction. The addition of NaOH could destroy the intermolecular hydrogen bond network of glycerol molecules, making the hydroxyl groups bared in free state, and increase the amount of electrophilic transition state of acetone, which help to promote the transformation of glycerol to solketal significantly. With the assistance of NaOH, the conversion rate of glycerol could even reach 97.58 % without extracting water continuously from the reaction system.
研究领域:
化学工程
·
催化
·
可再生能源
·
可持续化学
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2023
·Vol. 15
·期 20
·9049-9059
·
IF 6.7
Xiaolong Deng,Shanshan Wang,Yi Liu,Jiafeng Cao,Jinzhao Huang,Xingwei Shi
In this study, a hierarchical interconnected porous metal sulfide heterostructure was synthesized from CoFeAl layered double hydroxides (LDHs) by a two-step hydrothermal process (sulfidation and a NaOH etching process). Among the as-made samples, the CoFeAl-T-NaOH electrode exhibited excellent oxygen and hydrogen evolution reaction catalytic activities with overpotentials of 344 mV and 197 mV at the current density of 100 mA cm−2, respectively. Meanwhile, small Tafel slopes of 57.7 mV dec−1 and 106.5 mV dec−1 for water oxidation and hydrogen evolution were observed for the CoFeAl-T-NaOH, respectively. Serving as both the cathode and anode for overall water splitting, the CoFeAl-T-NaOH electrode reached a current density of 10 mA cm−2 at a cell voltage of 1.65 V with excellent stability. The enhanced electrocatalytic activity could be attributed to: the hierarchical interconnected nanosheet structure facilitating mass transport; the porous structure promoting electrolyte infiltration and reactant transfer; the heterojunction accelerating charge transfer; and the synergistic effect between them. This study offered a new clue for in situ synthesizing porous transition-metal based heterojunction electrocatalysts with a careful tuning of the sequence of sulfuration and alkaline etching to enhance the electrocatalytic performance.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2021
·
IF 6.165
Yuhuan Deng,Bin Liang,Xingtang Liang,Songlin Fan,Yanjuan Zhang,Yanzhen Yin,Huayu Hu,Zuqiang Huang,Yuben Qin
Chitin is difficult to be dissolved due to its dense structure, high crystallinity, and acetyl groups. Amorphization is conducive to enhancing the solubility of chitin. In this study, an effective mechanical activation-metal salt (MAMS) technology was used to pretreat α-chitin to improve its solubility in NaOH/urea solution. The chlorides of Fe and Al showed better synergistic effect with MA, especially FeCl 3 . The crystallization index of MA-FeCl 3 -pretreated chitin (MAFCCT) decreased to 4%, attributing to that Fe 3+ and Cl - jointly disrupted the intra- and intermolecular-hydrogen bonds in chitin. In addition, during the dissolution of MAFCCT, Fe 3+ fixed on chitin could form Fe(OH) 3 colloid with OH – to induce NaOH enter the interior of chitin molecules. The solubility of MAFCCT in NaOH/urea solution at −16 °C for 8 h reached 97.1%. MAMS pretreatment is a practical technology to enhance the solubility of chitin by destroying its stable crystal structure.
研究领域:
生物化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2023
·
IF 4.1
Angxin Tong,Xiaojun Tang,Haibin Liu,Honghu Gao,Xiaofei Kou,Qiang Zhang
The aim of this study is to enhance the classification performance of the back-propagation-artificial neural network (BP-ANN) algorithm for NaCl, NaOH, β-phenylethylamine (PEA), and their mixture, as well as to avoid the defects of the artificial bee colony (ABC) algorithm such as prematurity and local optimization. In this paper, a method that combined an improved adaptive artificial bee colony (IAABC) algorithm and BP-ANN algorithm was proposed. This method improved the ABC algorithm by adding an adaptive local search factor and mutation factor; meanwhile, it can enhance the abilities of the global optimization and local search of the ABC algorithm and avoid prematurity. The extracted score vectors of the principal component of the ultraviolet (UV) spectrum were used as the input variable of the BP-ANN algorithm. The IAABC algorithm was used to optimize the weight and threshold of the BP-ANN algorithm, and the iterative algorithm was repeated until the output accuracy was reached. The output variable was the classification results of NaCl, NaOH, PEA, and the mixture. Meanwhile, the proposed IAABC-BP-ANN algorithm was compared with discriminant analysis (DA), sigmaid-support vector machine (SVM), radial basis function-SVM (RBF-SVM), BP-ANN, and ABC-BP-ANN. Then, the above algorithms were used to classify NaCl, NaOH, PEA, and the mixture, respectively. In the experiment, four indicators, accuracy, recall, precision, and F-score, were used as the evaluation criteria. In addition, the regression equation parameters of the mixture for the testing set were obtained by BP-ANN, ABC-BP-ANN, and IAABC-BP-ANN models. All of the results showed that IAABC-BP-ANN exhibits better performance than other algorithms. Therefore, IAABC-BP-ANN combined with UV spectroscopy is a potential identification tool for the detection of NaCl, NaOH, PEA, and the mixture.
研究领域:
化学信息学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DESALINATION
·
2021
·
IF 9.501
Ruijun Zhang,Song Su,Shanshan Gao,Jiayu Tian
Flexible regulation of the membrane performance via the reconstruction of structural and physicochemical features is a promising technical route for the modification of nanofiltration (NF) membranes. Here we present a facile but effective post-treatment method with a ternary mixture of Ethanol-Water-NaOH (EWN). It was demonstrated the polyamide (PA) film in the nascent NF membrane could be effectively reconstructed by the EWN which consisted of 1 mol/L NaOH , 70% ( v /v) ethanol, and 30% (v/v) ultrapure water. The EWN post-treatment greatly improved the water permeability (almost 100%) while maintaining high Na 2 SO 4 rejection (~95.9%), which made membrane separation performance closer to the “upper bound” related to the “trade-off” between water permeability and Na 2 SO 4 rejection. This improvement was attributed to the “etching effect” brought by the synergistic interaction between NaOH and ethanol, which partially broke the polyamide chains, thus reducing the PA film thickness from 43.1 nm to 18.5 nm, decreasing the water contact angle from 38° to 28°, and decreasing the zeta potential from −34.4 mV to −69.1 mV. In addition, the long-term stability testing up to 60 h verified the good durability of the post-treated PA film. The performance improvement of different commercial NF membranes confirmed the general applicability of EWN post-treatment.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 51
·29772-29778
·
IF 3.049
Longfei Zhang,Li Yang,Yewei Xu,Guanjun Chang
A novel porous organic material 4-hydroxyindole-formaldehyde/NaOH (4-HIF/NaOH) aerogel was prepared via a facile polymerization, soaking in NaOH aqueous solution and ambient drying method. 4-HIF/NaOH aerogel porous polymer networks with high surface area have been applied as efficient adsorbents to remove methylene blue from wastewater via synergistic effects of cation–π interaction induced electrostatic interaction, electrostatic interaction and π–π interaction. The adsorption capacity calculated by adsorption isotherms at 303 K was 1016.9 mg g−1 which is higher than those observed for methylene blue on other aerogels and most other materials. Furthermore, the methylene blue loaded 4-HIF aerogel can easily be regenerated with 0.1 M HCl solution and ethanol wash, retaining over 75% of the adsorption capacity after recycling five times.
研究领域:
环境科学
·
材料科学
✓ 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）