CATALYSIS LETTERS
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2020
·Vol. 150
·期 9
·2709-2715
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IF 2.482
Mao Fei-Feng,Zhao Wenguang,Tao Duan-Jian,Liu Xianxiang
Abstract A new solid acid catalyst Fe 3 O 4 @TNTs-SO 3 H was successfully prepared, characterized, and applied for efficient conversion of renewable levulinic acid to n -butyl levulinate, serving as a promising liquid fuel additive. This catalyst was demonstrated to show high catalytic activity and afford n -butyl levulinate with a yield of 94.6% under optimum conditions. Graphic Abstract
研究领域:
化学工程
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催化材料
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能源化学
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产品关联
DOI
高影响因子
Catalysts
·
2020
·Vol. 10
·期 6
·692
·
IF 3.52
Yan Du,Xiao Chen,Ji Qi,Pan Wang,Changhai Liang
The electrocatalytic hydrogenation (ECH) of biomass-derived levulinic acid (LA) is a promising strategy to synthetize fine chemicals under ambient conditions by replacing the thermocatalytic hydrogenation at high temperature and high pressure. Herein, various metallic electrodes were investigated in the ECH of LA in a H-type divided cell. The effects of potential, electrolyte concentration, reactant concentration, and temperature on catalytic performance and Faradaic efficiency were systematically explored. The high conversion of LA (93%) and excellent “apparent” selectivity to valeric acid (VA) (94%) with a Faradaic efficiency of 46% can be achieved over a metallic lead electrode in 0.5 M H2SO4electrolyte containing 0.2 M LA at an applied voltage of −1.8 V (vs. Ag/AgCl) for 4 h. The combination of adsorbed LA and adsorbed hydrogen (Hads) on the surface of the metallic lead electrode is key to the formation of VA. Interestingly, the reaction performance did not change significantly after eight cycles, while the surface of the metallic lead cathode became rough, which may expose more active sites for the ECH of LA to VA. However, there was some degree of corrosion for the metallic lead cathode in this strong acid environment. Therefore, it is necessary to improve the leaching-resistance of the cathode for the ECH of LA in future research.Keywords:electrocatalytic hydrogenation;levulinic acid;valeric acid;lead
研究领域:
化学工程
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
Animal
·
2017
·Vol. 12
·期 3
·491-500
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IF 1.921
Q. Liu,C. Wang,G. Guo,W. J. Huo,Y. L. Zhang,C. X. Pei,S. L. Zhang,H. Wang
Isovalerate supplements could stimulate rumen development by improving morphology and function of rumen mucosa, and then promote the growth of calves. This study was done to evaluate the effects of isovalerate supplements on morphology and functional gene expression of rumen mucosa in dairy calves. In total, 48 Chinese Holstein male calves with 15 days of age and 45.1±0.36 kg of BW were randomly assigned to four groups. The treatments were: control, low-isovalerate, moderate-isovalerate and high-isovalerate with 0, 3, 6 and 9 g isovalerate per calf per day, respectively. Supplementary isovalerate was hand-mixed into milk in pre-weaning calves and into concentrate portion in post-weaning calves. The study consisted of a 15-day-adaptation period and a 60-day-sampling period. Calves were weaned at 60 days of age. Three calves were slaughtered from each of the four treatments at 30, 60 and 90 days of age. The weight of body and stomach were measured, samples of ruminal tissues and blood were analyzed. Total stomach weight, total stomach to BW ratio, rumen wall and keratinized layer thickness, serum growth hormone and IGF-1 for both pre- and post-weaning calves increased linearly with increasing isovalerate supplements. Rumen to total stomach weight ratio, the length and width of rumen papillae, and serum β-hydroxybutyrate increased linearly for post-weaning calves. However, abomasum weight to total stomach weight ratio decreased linearly for both pre- and post-weaning calves. The relative messenger RNA expression for growth hormone receptor, IGF-1 receptor and 3-hydroxy-3-methylglutaryl-CoA synthase 1 in rumen mucosa increased linearly for post-weaning calves. Our results suggested that isovalerate supplements promoted rumen development in a dose-dependent manner. The optimum dose was 6.0 g isovalerate per calf per day.
研究领域:
动物科学
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分子生物学
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DOI
PubMed
高影响因子
Polymers
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2023
·Vol. 15
·期 18
·3728
·
IF 5
Lin Zhang,Xiaofei Zhang,Yingcai Gui
Coordination polymers (CPs) have attracted greater scientific attention as promising electrode materials for lithium–ion batteries (LIBs) due to their diverse and versatile structural chemistry. This study introduces a croconate-based one-dimensional CP, namely [Fe(C5O5)(H2O)3]n) (referred to as Fe-CP), as an efficient anode material with high-performance characteristics for rechargeable LIBs. The ligand with abundant redox sites coordinating to the transition metal ion endowed the anode material with a remarkable stability in the electrolyte, in addition to high capacity, high-rate capability, and high cycling performance during charging/discharging process. The Fe-CP has a unique chain-based supramolecular structure, setting it apart from other porous three-dimensional molecular materials. The presence of unrestricted channels between the chains facilitates the diffusion of lithium ions in this unique structure. When tested at 100 mA g−1over a range of voltages between 0.01 and 2.4 V, the Fe-CP anode demonstrated a noteworthy specific capacity of 521 mA h g−1over 140 cycles. Moreover, the Fe-CP anode material exhibited excellent rate performance and demonstrated favorable cyclability. Following exposure to high charging and discharging rates of 2 A g−1, the anode ultimately regained its initial capability when the current rate was back at 100 mA g−1.Keywords:coordination polymers;one-dimensional;croconate-based;anode
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
International Journal of Coal Preparation and Utilization
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2019
·
IF 2.02
Zechen Liu,Yinfei Liao,Yongtian Wang,Maoyan An,Qingteng Lai
Low-rank coals are difficult to float using common hydrocarbon oily collectors, such as dodecane and diesel. In this investigation, a mixture of dodecane and n-valeric acid was used as a collector to enhance low-rank coal flotation. The changes in the induction time and surface functional groups of low-rank coal were measured before and after different collector’s adsorption to indicate its absorption mechanism. The surface free energy was calculated to identify the interaction mechanism quantitatively between coal and collectors. The results showed that the flotation performance using the mixture as a collector was much better than that using dodecane or n-valeric acid solely. The induction time of coal conditioned with the mixed collector was the shortest, which meant the better hydrophobicity and floatability. When used the mixture as collector, the polar group of the n-valeric acid interacting with the oxygenated functional group on the coal surface by hydrogen bond while dodecane primarily covers the hydrophobic sites on the coal surface. Additionally, the mixed collector can minimize the surface free energy of raw coal, the dodecane primarily reduces the nonpolar part of the coal surface free energy while the n-valeric acid reduces the polar part of the coal surface free energy.
研究领域:
矿物加工工程
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化学工程
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DOI
高影响因子
CELLULOSE
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2019
·Vol. 26
·期 15
·8313-8323
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IF 3.917
Wang Chao,Yang Guihua,Zhang Xueming,Shao Lupeng,Lyu Gaojin,Mao Jianzhen,Liu Shijie,Xu Feng
Levulinic acid (LA) production from corncob acid hydrolysis residues (CAHR) using FeCl 3 as Lewis acid catalyst in green solutions of salt was investigated. The reaction kinetic relationships were determined in the temperature range of 160–180 °C, with FeCl 3 concentrations of 0.12–0.36 M, and a reaction time of 0–60 min. The maximum LA concentration of 59.0 mol% (24.5 g/L) was achieved at 170 °C in a 30% NaCl solution containing 0.24 M FeCl 3 . A pseudo first-order kinetic model was proposed to describe the cellulose deconstruction to LA. The model agreed perfectly with the evolution in the concentrations of the major compounds such as glucose, 5-hydroxymethylfurfural and LA during the CAHR hydrolysis. The kinetic model developed for CAHR was in good agreement with that previously developed for other lignocellulosic systems. Based on our kinetic model and reaction system, the LA yield is increased at the lower end of the temperature range with the higher acid concentrations. The results indicated that the concentrated seawater after desalination could be a green solvent in the biorefinery.
研究领域:
化学工程
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生物技术
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
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2023
·
IF 6.7
Junbo Liu,Shengyang Tao
Electrocatalysis of biomass-derived platform molecules is an effective way to utilize biomass. Electrodes for the electrocatalytic hydrogenation of levulinic acid (LA) to selectively produce valeric acid (VA) have been extensively studied. Improving the electrocatalytic activity of electrodes for LA conversion is a meaningful and challenging task. This paper prepared β-PbO/Pb electrodes by laser processing. The higher adsorption of LA on the β-PbO surface was confirmed by in situ infrared and Raman spectra and density functional theory (DFT) calculations. The β-PbO/Pb electrode exhibited higher electrocatalytic activity than the α-PbO/Pb and Pb electrodes. Complete conversion of LA was achieved at a much lower electrode potential of −1.4 V (vs RHE) with an 85 % yield of VA and greater than 90 % selectivity. In addition, laser processing technology provides a strategy for the rapid processing of electrodes to enable large-scale continuous production in industry.
研究领域:
化学
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能源科学
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产品关联
DOI
高影响因子
JOURNAL OF NUTRITIONAL BIOCHEMISTRY
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2025
·
IF 4.9
Changtong Guo,Xiangda Shi,Bingbing Luo,Yuxuan Yang,Jian Huang,Jiale Xu,Rong Zheng,Siwen Jiang,Jin Chai
In actual production, the restraint stress caused by crowded and narrow spaces, as well as operations such as capture and transportation, can lead to intestinal inflammation and affect animal growth performance, damaging the economic benefits of livestock farms. Isovaleric acid, a type of short-chain fatty acid (SCFA), has been found to be useful in enhancing calf digestion and inhibiting the expression of inflammatory factors. In this study, we first constructed a mouse model of chronic restraint stress (CRS) and fed a diet supplemented with sodium isovalerate to mice with CRS to investigate the mitigating effect of exogenously added isovalerate on mice with chronic restraint stress. An inflammation model was then constructed using piglet jejunal epithelial cell line-J2 (IPEC-J2) to simulate intestinal inflammation after stress, and to investigate the mitigating effect of isovaleric acid on inflammation as well as the repairing effect on intestinal barrier. The results showed that feeding sodium isovalerate significantly increased the weight gain as well as the body weight growth rate of CRS mice from 1-28 days ( P < 0.05), and extremely significantly decreased the feed intake and feed to gain ratio of CRS mice ( P < 0.01). In addition, feeding sodium isovalerate ameliorated the decrease in organ index in mice caused by CRS and significantly increased leg muscle index in CRS mice ( P < 0.05). Meanwhile, feeding sodium isovalerate improved depressive behavior and promoted 5-HT secretion in the brain and hypothalamus of CRS mice. Besides, feeding sodium isovalerate ameliorated intestinal inflammation in CRS mice, as evidenced by extremely significantly decreased the expression of colonic inflammatory factors and increased the expression of tight junction proteins ( P < 0.01). It was found that the addition of isovaleric acid extremely significantly reduced the expression of inflammatory factors and the phosphorylation level of NF-κB p65 in inflammatory cells ( P < 0.01), extremely significantly increased the survival rate of inflammatory cells ( P < 0.01) and the expression of tight junction proteins ( P < 0.05), improved the morphology of inflammatory cells. After the addition of short-chain fatty acid receptor GPR41 and GPR43 antagonists, the resistance effect of isovaleric acid on inflammation was inhibited. The above results suggest that isovaleric acid has an ameliorating effect on CRS in mice and inhibits NF-κB activation thereby exerting its anti-inflammatory effect.
研究领域:
生物化学
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免疫学
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动物营养学
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产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
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2017
·
IF 5.951
Xueyan Zhang,Yue Li,Lifang Xue,Shengtian Wang,Xiaohong Wang,Zijiang Jiang
A series of Lewis acid metals monosubstituted phosphotungstic acids HnPW11MO39 (HPWM, M = CuII, ZnII, CrIII, FeIII, SnIV, TiIV, and ZrIV; for Ti and Zr, the number of oxygen is 40) was evaluated in direct production of methyl levulinate (ML) from cellulosic biomass in a cascade reaction. One of the solid catalysts, H5PW11TiO40 (HPWTi), was found to be highly efficient for generation of ML from mono- or polysaccharides, reaching 51.3% ML yield directly from cellulose. And under microwave-assistance, the efficiency could be improved to a 62.6% ML yield within 2 h, which was almost the best result so far among reported solid catalysts. Identification of the reaction intermediates and the products provided some insight into the reaction mechanism and showed the requirement of certain Brønsted/Lewis acid ratio as 2.84/1 for HPWM. Moreover, the different metals in catalysts profoundly affected the Lewis or total acidity, and therefore, the catalytic activity and selectivity to ML or methyl glucosides (MG). HPWTi acted as a heterogeneous catalyst after being calcinated at 200 °C and showed high recyclability with minor loss of performance.
研究领域:
化学工程
·
生物质能
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
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2022
·Vol. 46
·期 15
·23551-23563
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IF 4.672
Xiaoman Gong,Yi Shen
Summary Converting carboxylic acids into value-added products by electrochemical processes is of great interest. In this work, the electrochemical conversion of valeric acid (VA) on carbon materials including glassy-carbon (GC) electrodes and carbon-paper (CP) electrodes was studied. Owing to the porous structure, CP electrodes showed superior performance relative to GC electrodes. The surface properties of CP electrodes were modified via electro-oxidation processes. The structures of the CP electrodes were characterized by scanning electron microscopy, X-ray diffraction pattern, X-ray photoelectron spectroscopy spectra, and Raman spectra. It was found that the electrochemical activation process had more pronounced effects on electro-oxidation of VA than H 2 O. The onset potential of VA oxidation on electrochemically activated CP electrodes was negatively shifted and the current density was significantly improved. The products of VA oxidation by CP electrodes were determined by gas chromatography-mass spectra. VA was mainly transformed into 2-butanol, butyl valerate, and pentanoic acid 1-methylpropyl ester. The conversion of VA, Faraday efficiency, and product selectivity were determined. The optimal CP electrode exhibited the largest values of product selectivity (85.0%) and VA conversion (13.0%). In-situ Raman spectra were recorded to study the mechanism of VA oxidation on the CP electrodes. The oxidation of VA by CP electrodes follows the non-Kolbe route and the corresponding pathway was proposed.
研究领域:
电化学
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材料科学
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产品关联
DOI
高影响因子
Reaction Chemistry & Engineering
·
2021
·Vol. 6
·期 10
·1811-1818
·
IF 4.239
Hongxing Wang,Guoqiang Ding,Yubo Liu,Junbo Zhang,Yongwang Li,Yulei Zhu
A sustainable and cost-competitive catalytic process for high yield production of levulinic acid (LA) and γ-valerolactone (GVL) from biomass-derived furfuryl alcohol (FOL) fluid was proposed with GVL as a self-circulation solvent. The innovative process eliminated the separation of the final product GVL and intermediate product LA from the solvent, and the actual concentration of FOL was improved enormously. A higher yield (90.5%) of LA was realized in the fixed-bed reactors than that in the conventional autoclave since the short residence time of the FOL solution could alleviate the polymerization of FOL in the continuous process. UV-Raman spectroscopy demonstrated that fewer polymers deposited on the catalysts, so superior stability of the zeolite was observed in the fixed-bed reactors. Moreover, an 89.4% high yield of GVL can be achieved since the integration of the tandem reaction of hydration and hydrogenation could substantially avoid side reactions in the fixed-bed reactors.
研究领域:
化学工程
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
THERAPEUTIC DRUG MONITORING
·
2015
·Vol. 37
·期 6
·776
·
IF 2.376
Zhang Zhi-qing,Dong Wei-chong,Yang Xiu-ling,Zhang Jin-feng,Jiang Xin-Hui,Jing Shao-jun,Yang Hong-le,Jiang Ye
Background: Free drug analysis is increasingly becoming popular in therapeutic drug monitoring (TDM). Centrifugal ultrafiltration (CF-UF) is the primary method to separate free drug from that of bound drug. However, the volume ratio of ultrafiltrate to sample solution ( V u / V s ) affects the accuracy of CF-UF, which highly depends on the different plasma conditions. Plasma protein concentrations in patients are different from those observed in healthy subjects, and there are also significant differences among patients with different diseases. Only very few studies have reported on the effect of protein concentration on the analysis methodology of free drug by CF-UF. Methods: In this study, valproic acid was used as the representative drug, and plasma samples with different albumin concentrations were analyzed by CF-UF and hollow fiber centrifugal ultrafiltration (HFCF-UF). Results: There was no significant difference of free drug concentrations by HFCF-UF and CF-UF when plasma albumin concentrations ranged 40–60 g/L. However, at low albumin concentrations (<40 g/L), a considerable difference was detected, and the difference was increased with the decrease of plasma albumin concentration. When the albumin concentration was as low as 10 g/L, the free drug concentration was 17.3 mcg/mL by CF-UF, whereas it was 10.2 mcg/mL by HFCF-UF. Conclusions: The accuracy of free drug measurement by CF-UF was albumin concentration dependent. However, such an effect was not observed when samples were prepared by HFCF-UF, which was more suitable for TDM of plasma samples from different patients. Therefore, this method could be readily applied to the measurement of free valproic acid plasma concentrations for TDM in patients.
研究领域:
药理学
·
临床医学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）