Catalysis Science & Technology
·
2023
·Vol. 13
·期 6
·1748-1754
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IF 5
Shaoyuan Guo,Xinli Tong,Lingwu Meng,Guobao Yang
Selective oxidative C–C and C–O bond cleavage is of significance to the efficient utilization of biomass and biomass-derived platform compounds. In this work, the selective oxidative cleavage of C–C and C–O bonds has been developed with an iron-based catalyst (Fe–N–C) in the presence of molecular oxygen. Specifically, the β-O-4 lignin model compound was successfully converted to phenol and methyl benzoate in a methanol solvent, where the substrate conversion was 95.0% and the yields of phenol and methyl benzoate were 94.9% and 63.7%, respectively, when the reaction was performed with the Fe–N–C-850 catalyst at 120 °C for 4 h. Also, the oxidative transformations of other lignin models to phenols and methyl benzoates were achieved. Further investigations showed that the existence of the Fe3C phase in the catalyst plays an important role in the aerobic oxidative cleavage of C–C and C–O bonds in the β-O-4 lignin model.
研究领域:
生物质化学
·
催化化学
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产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2020
·Vol. 22
·期 20
·11508-11518
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IF 3.43
Jing Chen,Hanling Yang,Hongquan Fu,Hongyan He,Qiang Zeng,Xuehui Li
Electrochemical oxidation is a promising and effective method for lignin depolymerization owing to its selective oxidation capacity and environmental friendliness. Herein, the electrooxidation of non-phenolic alkyl aryl ether monomers and β-O-4 dimers was experimentally (by cyclic voltammetry, in situ spectroelectrochemistry, and gas chromatography-mass spectroscopy) and theoretically (by DFT calculations) explored in detail. Compared to the reported literature (T. Shiraishi, T. Takano, H. Kamitakahara and F. Nakatsubo, Holzforschung, 2012, 66(3), 303–309), 1-(4-ethoxyphenyl)ethanol showed a distinguishable oxidation pathway, where the resulting carbonyl product surprisingly underwent a bond cleavage on alkyl–aryl ether to ultimately produce a quinoid like compound. In contrast, β-O-4 dimers, like 2-phenoxy-1-phenethanol and 2-phenoxyacetophenone also demonstrated electrochemical oxidation induced by Cβ–O and Cα–Cβ bond cleavages. For the oxidation products, the presence of the Cα-hydroxyl group in dimers was the key to selectively generate aldehyde-containing species under mild electrochemical conditions, otherwise it produces alcohol-containing products following a different mechanism compared to the CαO containing dimers.
研究领域:
林产化学
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环境科学
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有机化学
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产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2020
·
IF 3.687
Yang Zhong,Bo Zhou,Lijun Wang
Fe/FeO x embedded in LDH was prepared by reducing the pre-synthesized [Fe(C 2 O 4 ) 3 ] 3− anions intercalated LDH and used as a multi-functional catalyst for synthesis of C7-C9 compound via transfer hydrogenation between furfural (C5) and short-chain alcohols (C2-C4) and a subsequent aldol reaction of furfural with intermediate short-chain aldehydes in the absence of a homogeneous base with furfuryl alcohol as a byproduct. Screening reaction conditions, evaluation and improvement of the cyclic catalytic performance, and determination of catalytically active components were performed, and the results demonstrated that both high conversion and high selectivity to the C C bond forming product can be obtained under a non-oxidizing atmosphere of Ar or H 2 /Ar mixed gas, a reaction temperature of 140 °C and a reaction time of 4 h; the catalyst was easily deactivated during the cycle experiments, however, its catalytic stability can be effectively improved by depositing Ni with weak reducibility on the surface of Fe nanoparticles at the cost of reducing partial catalytic activity. Fe/FeO x together with LDH as a whole proved to be effective in catalyzing the transfer hydrogenation reaction and the support LDH imparted basic catalytic function to the composite realizing the aldol reaction in the absence of a homogeneous base.
研究领域:
催化化学
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材料科学
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绿色化学
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产品关联
DOI
高影响因子
Asian Journal of Organic Chemistry
·
2018
·Vol. 7
·期 10
·2039-2044
·
IF 2.496
Qian-Qian Huang,Wei-Qiang Yu,Xiao-Lin Luo,Jin Gao,Jie Xu
Graphical An alternative method for glycerol hydrogenolysis to CH 4 and ethylene glycol that proceeds through preferential C−C bonds cleavage catalyzed by highly-dispersed Ru catalysts with tunable particle sizes via carbothermal reduction has been reported. An alternative method for the conversion of crude glycerol was proposed to produce renewable energy methane and high-value chemical ethylene glycol through preferential cleavage of C−C bonds, catalyzed by highly dispersed Ru-based catalysts prepared by carbothermal reduction. It was found that the Ru particles size could be tuned by adjusting the reduction temperature, and the size firstly decreased then increased with raising of the temperature of carbothermal reduction. This resulted in the opposite tendency of catalytic performance against the Ru particle sizes in hydrogenolysis of glycerol, in which the glycerol conversion and yield of C−C bond cleavage increased firstly and then decreased. Ru catalysts carbothermal reduced at 450 °C possessed highly dispersed Ru nanoparticles with uniform particle sizes about 1.0 nm that showed high hydrogenation activity and selectivity of C−C bond cleavage as well as good stability that could be recycled in aqueous phase hydrogenolysis of glycerol.
研究领域:
化学工程
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催化
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可再生能源
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绿色化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2025
·
IF 13.1
Shilun Wang,Wei Peng,Heliang Ma,Xingdi Pan,Yao Shen,Jingkai Zhao,Jiexu Ye,Qiaoli Wang,Pengfei Xie,Shihan Zhang,Xiang Gao
The electrocatalytic reduction of carbon dioxide (CO2RR) by copper oxide-based materials is conducive to the formation of high value-added products, but their activities and selectivities remain unsatisfactory. Organic ligand modification is a promising strategy to achieve a high CO2RR activity. Here, the modification of Cu2O with 1-butyl-3-methylimidazolium chloride (Bmim-Cu2O) enhanced the adsorption of reaction intermediates and improved the stability of the catalyst in the CO2RR, which displays a high Faradaic efficiency of ≈85% to C2+ products with a current density as large as ≈352.5 mA cm–2. In situ characterization reveals a stronger *CO signal with bridge configuration and a stronger *OCCHO signal over Bmim-Cu2O than unmodified Cu2O and can improve the stability during electrochemical CO2 reduction. Density functional theory calculations show that local molecular modulation can effectively regulate the electronic structure of Cu2O and enhance the adsorption of *CO and *CHO intermediates through the stabilization of a noncovalent interaction, which can greatly promote the asymmetric *CO–*CHO coupling in the electrochemical reaction process.
研究领域:
电化学
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催化
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材料科学
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环境科学
·
理论化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Junjie Xu,Wei Sun,Xiang Xiong,Hongbo Zhang,Lingkun Yang
To improve the mechanical properties and ablation resistance of Cf-reinforced ceramic-based materials, ZrC–W cermet composites (C/C–ZrC–W) were prepared in C/C preforms using slurries and low-temperature reactive melt infiltration , and their microstructure, formation mechanism, and mechanical and ablation properties were investigated. The obtained results revealed that the formation of C/C–ZrC–W composites involved the dissolution–precipitation and C diffusion processes. Owing to the precipitation of W nanoparticles in the ZrC phase and interdiffusion of W/ZrC, the fabricated C/C–ZrC–W composites exhibited superior mechanical properties with a flexural strength of 280.65 ± 12.84 MPa and fracture toughness of 13.87 ± 0.56 Mpa.m 1/2 . The formation of a Zr–W–O dense oxide layer resulted in the excellent ablation performance of the C/C–ZrC–W composites in oxyacetylene flame with a temperature of 2200 °C, and their mass ablation rate and linear ablation rate were 1.14 mg/s and 2.42 µm/s, respectively. The described method can be potentially used for preparing high-strength, high-toughness, and ablation-resistant materials at low temperatures.
研究领域:
材料科学
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航空航天工程
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产品关联
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2023
·
IF 6.1
Wenwen Yang,Xiaoping Zhang,Jun Zhang,Guoshuan Wang,Hailong Liang,Xinglei Zhang,Konstantin Chingin,Huanwen Chen
The positions of C═C bonds in unsaturated fatty acids (FAs) are one of the main factors determining the quality of food flavor. Herein, we developed an approach for the determination of C═C bonds of FAs by online epoxidation reaction with water dimer radical cations. The limit of detection for octenoic acid isomers was ∼9 μg/L. The positions of C═C bonds in trans-2/3-hexenoic acid, trans-2/3-octenoic acid, oleic acid, linoleic acid, and linolenic acid in black tea or olive oil samples were directly determined by the established method. These results indicate that the established method allows the rapid determination of unsaturated FAs in black tea and olive oil. The advantages of this approach include the analysis speed (∼1 min per sample), simple device, and no need for complex pretreatment. This study not only provides a strategy for the determination of C═C positions but also offers new possibilities for applications in the field of food chemistry.
研究领域:
分析化学
·
食品科学
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Su Wang,Qifang Sun,Chen Li,Dongge Wang,Yue Ma,Hongzhou Zhang,Xixi Shi,Lianqi Zhang,Dawei Song
Given the high combustion or explosion potential of liquid electrolyte, polymer electrolytes have attracted intensive attention due to high safety, compatible interface and flexible processability. However, the related low ionic mobility remains an issue for related wide application. Herein, a crosslinked polymer electrolyte (abbreviated as PMEP) comprising abundant oxygen-contained groups (C-O-C/C=O) is developed. With the crosslinking agent of ethoxylated trimethylolpropane triacrylate (ETPTA), a high transference number ( t Li + =0.69) is obtained since C-O/C=O are conducive to the transfer of Li ions. Specifically, C=O group exists in individual monomers in order to be applicable to high voltage cathode, therefore, a criss-cross network containing abundant sites conducive to ion transport is constructed and rapid ion transfer as well as enhanced mechanical strength can be realized even in high potential system. With the coordination effect of C-O and C=O, PMEP exhibits rapid Li ion transfer and a wide electrochemical stability window of 5.1 V. As for Li//Li symmetrical cell, a stable voltage profile with slight polarization of 60 mV is displayed for over 550 h at 1 mA cm −2 . After assembled with LiNi 0.8 Co 0.15 Al 0.05 O 2 cathode, a high discharge specific capacity of 190.6 mAh g −1 is delivered and the capacity retention reaches 86 % at 0.1C for 100 cycles. This work provides a promising method for designing high-performance polymer electrolytes for lithium metal batteries.
研究领域:
材料科学
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电化学
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能源存储
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产品关联
DOI
高影响因子
Nature Ecology & Evolution
·
2023
·Vol. 7
·期 11
·1892-1902
·
IF 16.8
Ju Yun,Zhang Hong,Jiang Yanxiao,Wang Wenxin,Kan Guangfeng,Yu Kai,Wang Xiaofei,Liu Jilin,Jiang Jie
The reverse tricarboxylic acid cycle (rTCA) is a central anabolic network that uses carbon dioxide (CO 2 ) and may have provided complex carbon substrates for life before the advent of RNA or enzymes. However, non-enzymatic promotion of the rTCA cycle, in particular carbon fixation, remains challenging, even with primordial metal catalysis. Here, we report that the fixation of CO 2 by reductive carboxylation of succinate and α-ketoglutarate was achieved in aqueous microdroplets under ambient conditions without the use of catalysts. Under identical conditions, the aqueous microdroplets also facilitated the sequences in the rTCA cycle, including reduction, hydration, dehydration and retro-aldol cleavage and linked with the glyoxylate cycle. These reactions of the rTCA cycle were compatible with the aqueous microdroplets, as demonstrated with two-reaction and four-reaction sequences. A higher selectivity giving higher product yields was also observed. Our results suggest that the microdroplets provide an energetically favourable microenvironment and facilitate a non-enzymatic version of the rTCA cycle in prebiotic carbon anabolism.
研究领域:
化学
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生物化学
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前生物化学
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生命起源
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Catalysis
·
2020
·
IF 12.35
Peng Zhou,Yuguang Chao,Fan Lv,Kai Wang,Weiyu Zhang,Jinhui Zhou,Hui Chen,Liang Wang,Yiju Li,Qinghua Zhang,Lin Gu,Shaojun Guo
Photocatalytic reforming of renewable and low-cost biomass is an alternative approach to synthesize high-value-added multicarbon compounds and hydrogen. However, the difficulty in activating the methyl group of biomass and simultaneously promoting the C–C coupling makes photocatalytic reforming still a great challenge. Herein, through the first-principles simulation calculation of the energy barrier of acetone dehydrogenation and conversion over a series of noble metal single atom (Ru, Rh, Pd, Ag, Os, Ir, Pt, and Au)-loaded TiO2 (MSA-TiO2) photocatalysts, we predict a Pt single atom-loaded TiO2 (PtSA-TiO2) photocatalyst that can enable methyl activation, CH3COCH2• radical formation, and hydrogen production most effectively from acetone, which is very significant for the synthesis of high-value-added multicarbon compounds by C–C coupling. This is well confirmed by our photocatalytic experiments, revealing that PtSA-loaded commercial P25-TiO2 exhibits the best photocatalytic activity of 3.87 mmol g–1 h–1 for the direct coproduction of high-value-added 2,5-hexanedione (HDN) and hydrogen from acetone with a selectivity of 93%, at least 13-fold higher activity than other noble metal (Ru, Rh, and Ir) single atoms or Pt nanoparticle-loaded ones. In situ attenuated total reflection infrared spectroscopy reveals that the PtSAs contribute to the effective methyl activation and simultaneously promote the formation of more intermediate CH3COCH2• radicals, which are further confirmed by in situ electron spin resonance spectroscopy.
研究领域:
化学
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材料科学
·
催化反应
✓ 已验证
产品关联
DOI
高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2022
·Vol. 194
·期 11
·4999-5016
·
IF 3.094
Ma Teng,Kong Weixi,Liu Yunting,Zhao Hao,Ouyang Yaping,Gao Jing,Zhou Liya,Jiang Yanjun
The application of immobilized enzymes in pharmaceutical and bulk chemical production has been shown to be economically viable. We demonstrate the exceptional performance of a method that immobilizes the old yellow enzyme YqjM and glucose dehydrogenase (GDH) on resin for the asymmetric hydrogenation (AH) of C = C bonds in a SpinChem reactor. When immobilized YqjM and GDH are reused 10 times, the conversion of 2-methylcyclopentenone could reach 78%. Which is because the rotor of the SpinChem reactor effectively reduces catalyst damage caused by shear force in the reaction system. When the substrate concentration is 175 mM, an 87% conversion of 2-methylcyclopentenone is obtained. The method is also observed to perform well for the AH of C = C bonds in other unsaturated carbonyl compounds with the SpinChem reactor. Thus, this method has great potential for application in the enzymatic production of chiral compounds.
研究领域:
生物催化
·
酶工程
·
药物化学
·
有机合成
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2023
·Vol. 58
·期 22
·9196-9209
·
IF 4.5
Tang Zhen-xiao,Yi Mao-zhong,Zhou Yuan-ming,Liu Rui-zhi,Peng Ke
A three-dimensional orthogonal woven C/C-SiC composite was successfully prepared by high-solid-loading slurry impregnation combined with precursor infiltration and pyrolysis. The microstructure, mechanical properties and ablation behavior of the C/C-SiC composite were investigated. The slurry impregnation and the precursor infiltration and pyrolysis acted as fast filling and supplementary densification, respectively. Based on a three-dimensional orthogonal woven C/C preform, the C/C-SiC composite had excellent mechanical properties with bending strength and fracture toughness of 364.46 and 22.86 MPa·m 1/2 . The mass and linear ablation rates of the C/C-SiC composite were 3.21 mg/s and 4.93 μm/s, respectively, after ablation under an oxyacetylene flame for 300 s. The good ablation performance was attributed to the passive oxidation of SiC at high temperature and high oxygen partial pressure, and the pitting caused by SiO 2 accelerated the failure of carbon fibers.
研究领域:
材料科学
·
复合材料工程
·
高温结构材料
·
航天热防护材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）