Energy Conversion and Management-X
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2021
·
IF 0
Shaoqu Xie,Zhuoxi Li,Guodian Zhu,Conghua Yi
The world production of chemicals and fuels is predominantly based on the conversion of nonrenewable raw materials, such as coal, natural gas, and oil. Nowadays, there are increasing ways to produce fuels from biomass, such as producing fuel alcohol from lignocellulose, obtaining liquid fuels through carbon bond coupling of fermentation products to produce fuels. Herein, we transformed the short-chain acetone-n-butanol-ethanol (ABE) into long-chain straight-chain, branched, and cyclic jet-fuel-range products via self-condensation of acetone, Guerbet reaction of ABE, Pd/C-KOH/K 3 PO 4 catalyzed alkylation, and the separation was carried out simultaneously. After the condensation reaction of ABE catalyzed by KOH/K 3 PO 4 with or without Pd/C at high temperature, the ABE can be transformed into long-chain substances ranging from C7 to C12 (lower than 5% yield), which can be used as the precursor of the high-value fuels. Furthermore, most of the water in the ABE solution can be removed, and the water content decreased from 60 % to about 5%–8%. Future work will be concentrated on more liquid–liquid equilibria data of the ABE-water system at different temperatures and the design of highly-efficient catalysts to improve the reaction rate and the selectivity to the desired straight-chain, branched, and cyclic C7-C12 products.
研究领域:
化学工程
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可再生资源
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能源科学
✓ 已验证
产品关联
DOI
Royal Society Open Science
·
2020
·Vol. 7
·期 10
·
IF 2.646
Xiujing Peng,Shah Zeb,Jianguo Zhao,Miaomiao Zhang,Yu Cui,Guoxin Sun
HRF5015, a perfluorosulfonic acid resin catalyst with unique pore structures, was investigated in the catalytic self-condensation of cyclohexanone under mild conditions. The morphology of HRF5015 was characterized by transmission electron microscopy (TEM) and atomic force microscope (AFM), and the reaction mechanism was studied by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The effects of reaction time and temperature on the yield of dimer were investigated under the nitrogen atmosphere. The results show that the reaction temperature is low, and especially, the selectivity of the dimer is close to 100%. The apparent activation energy for the dimer formation reaction is 54 kJ mol−1. Synergistic action of cluster structure formed by sulfonic groups and nanopores in HRF5015 may be the key factor of high-efficiency catalytic activity and high selectivity. In situ infrared spectra indicate that the intermediate is stable in the reaction process. HRF5015 is environmentally friendly and re-usable, which shows good potential in a future application.
研究领域:
化学工程
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催化材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
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2024
·
IF 3.9
Haoxi Jiang,Hanwen Gu,Lingtao Wang,Guochao Yang
Zr-BEA zeolite was introduced to the aldol condensation of acetaldehyde and showed high crotonaldehyde selectivity (over 85%), but it suffered from rapid deactivation, where the conversion of acetaldehyde decreased from 16.4% at 1 h to 6.5% at 8 h. The spent Zr-BEA zeolites at different time-on-stream (TOS = 1, 2, 4, 6, and 8 h) were characterized by SEM, XRD, XPS, FT-IR, TGA, N 2 physical adsorption, and GC–MS to understand the deactivation mechanism. Pore blocking and Zr active site coverage caused by carbonaceous deposits were both responsible for the deactivation. Furthermore, the main carbonaceous species were unsaturated aldehydes, unsaturated ketones, and aromatic compounds.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
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2024
·
IF 3.9
Hanwen Gu,Guochao Yang,Lingtao Wang,Haoxi Jiang
Metal-incorporated *BEA zeolites have shown remarkable catalytic performance in the self-aldol condensation of various aldehydes. The substitution of heteroatom sites can modulate the self-aldol condensation performance of aldehydes, while the underlying mechanisms have been insufficiently explored, with even less attention given to acetaldehyde-related processes. Herein, seven transition metal-incorporated *BEA zeolites were post-synthesized and applied in the self-aldol condensation of acetaldehyde. All the M-BEA zeolites exhibited excellent crotonaldehyde selectivity, exceeding 80 % and most surpassing 85 %, with various acetaldehyde conversions. SEM, XRD, N 2 physisorption, FT-IR, UV–Vis, XPS, Py-IR, and NH 3 -TPD were employed to characterize the physicochemical properties. The M-BEA zeolites predominantly exhibit Lewis acidity, and the amount of Lewis acid with medium strength dominated the acetaldehyde conversion variations. The probe-pulse and TPSR experiments were further employed to investigate the reaction pathways to explain the product distribution on the Zr-BEA zeolite, which demonstrated the highest crotonaldehyde yield. The main side products were long-chain unsaturated aldehydes and cyclic compounds from excessive aldol condensation and cyclization. A reaction network for acetaldehyde conversion on Zr-BEA zeolite was ultimately proposed.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
DENTAL MATERIALS
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2018
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IF 4.039
Chenmin Yao,Jian Yu,Yake Wang,Chuliang Tang,Cui Huang
Objectives Some silane-containing universal adhesives were introduced that a separate ceramic primer was unnecessary to glass-ceramic bonding because of incorporated silane. We aimed to investigate the effectiveness of silane in universal adhesives with acidic media. Methods A functional γ-methacryloxypropyltrimethoxysilane (γ-MPTS) was used, and its pH value was adjusted to 2.7 by adding hydrochloric acid (HCl) or 10-methacryloxydecyl phosphate (MDP). The prepared acidic silane solutions after 2 h or 10 d storage were characterized by Fourier transform infrared spectroscopy (FTIR), 1 H and 13 C nuclear magnetic resonance (NMR) spectroscopy. Micro-shear bond strength (μSBS) was used to evaluate the bonding performance of glass ceramics. Two silane-containing and two silane-free universal adhesives were included. Field-emission scanning electron microscopy fractography analysis was also performed. Results FTIR, 1 H and 13 C NMR revealed that the hydrolysis of γ-MPTS and the self-condensation reaction of silanol groups occurred over time under acidic conditions (HCl or MDP solution). This reaction formed the siloxane oligomers. For glass-ceramic bonding, the μSBS of acidic silane after 10 d storage was lower than that of silane stored for 2 h storage ( p < 0.05), although the difference among the μSBS of the four universal adhesives were nonsignificant ( p > 0.05). Additionally, cohesive failure was the main fracture pattern of universal adhesive bonding. Significance The effectiveness of silane contained in low pH universal adhesives can be weakened by dehydration self-condensation and consequently became unstable. For the enhancement of glass-ceramic bonding efficiency with universal adhesives, a separate ceramic primer was recommended.
研究领域:
牙科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
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2018
·
IF 6.14
Mengjie Wu,Hui Ma,Zhongyi Ma,Yufang Jin,Chunyan Chen,Xiaoya Guo,Yan Qiao,Christian Marcus Pedersen,Xianglin Hou,Yingxiong Wang
Deep eutectic solvents (DESs) exhibit similar physicochemical properties to the ionic liquids. They are inexpensive, renewable, nontoxic, and environmentally benign solvents and have gradually attracted attention in several fields, for example, biorefinery. Here choline chloride-based DESs have been used as solvents and catalysts for the preparation of deoxyfructosazine (DOF) through a self-condensation reaction of d-glucosamine (GlcNH2). The catalytic performances of a “green cocatalyst”, amino acids, and the reaction mechanism were also studied. The results displayed that choline chloride/urea was capable to convert GlcNH2 efficiently, with a 13.5% yield of DOF at low temperature and with a short reaction time (100 °C, 150 min). Among the screened amino acids, arginine showed the highest activity and gave the highest yield of DOF (30.1%) under the optimized reaction conditions. Nuclear magnetic resonance (NMR) studies revealed a strong hydrogen bond interaction between GlcNH2 and arginine. Moreover, a detectable intermediate, namely dihydrofructosazine, in the condensation of GlcNH2 to DOF/fructosazine (FZ) was captured by in situ NMR technique.
研究领域:
有机化学
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绿色化学
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2022
·Vol. 139
·期 32
·e52765
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IF 3.057
Pengjia Shan,Hengyu Lu,Ning Chen,Hongzhi Liu,Xianhui Zhang,Xiaohuan Liu
Designing biobased hyperbranched polyesters from vegetable oil has been attracting considerable interests from academic industrial communities. Herein, a novel fully biobased hyperbranched polyester (HBPE) was prepared by self-condensation of AB 2 -type bioderived monomer based on methyl ricinoleate (MR), a castor oil-derived renewable chemical. The reaction conditions were optimized to obtain the AB 2 -type monomer in a high conversion ratio (up to 87%). The self-condensation of AB 2 -type monomers was carried out in the presence of two kinds of transesterification catalysts (Ti(OBu) 4 versus Zn(Ac) 2 ), among which Ti(OBu) 4 was found to be more efficient one and yield higher molecular weights in the range of 5800~11,500 g/mol. The resulting HBPEs were characterized in terms of Fourier transform infrared spectroscopy, nuclear magnetic resonance, differential scanning calorimetry, and thermogravimetric analysis. The degree of branching was calculated to be 0.33~0.39. Thermal analysis revealed that the as-prepared HBPEs were amorphous with tunable glass transition temperatures ranging from −44.8 to −24.6°C. All the prepared HBPEs exhibited good thermal stability with the maximum onset decomposition temperature ( T onset ) up to 294.6°C. These structural features and properties of resulting biobased HBPEs enabled them to act as a potential ‘greener’ additive for polymers.
研究领域:
材料科学
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生物基材料
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有机化学
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
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2025
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IF 9.2
Yaling Zhao,Deqing Zhao,Jingpeng He,Kaibin Ma,Jiatian Zhu,Jianrong Liu,Yongqi Zhang,Qinqin Xia,Ting Li
A lignin-first separation strategy can help improve the economic and environmental benefits of biorefinery. However, the self-condensation of lignin remains an insurmountable bottleneck in its isolation and valorization process. Therefore, the challenge of lignin separation is how to achieve a highly uncondensed lignin with high yield and high purity. In this work, we developed a ternary deep eutectic solvent (DES) based on polyhydric alcohols, which can be used to treat moso bamboo at 80–90 °C to obtain highly uncondensed lignin which is light-colored and highly active. The uncondensed lignin exhibits a high β-O-4 retention rate, up to 52.82/100Ar, accounting for 90.24% of the β-O-4 content in the raw material. At the same time, the maximum yield and purity of uncondensed lignin can reach 33.6% and 95.5%, respectively. Furthermore, through DFT theoretical calculations, we have proved that the lignin protection strategy by 1,2-propanediol is achieved by grafting the hydroxyl functional group to the α position of the benzylic carbocation intermediate, thus revealing the intrinsic mechanism by which polyol effectively blocks lignin condensation. The lignin-first fractionation strategy based on ternary deep eutectic solvents with polyhydric alcohols and Lewis acids overcomes the defects of lignin condensation that is inevitable during lignin separation and depolymerization. It obtains highly uncondensed lignin with high yield and high purity, and provides a new idea for biorefinery under the lignin-first separation strategy.
研究领域:
生物化学
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材料科学
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可再生资源工程
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2015
·Vol. 6
·期 21
·4020-4029
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IF 5.52
Jianbing Huang,Lvhuan Lin,Hui Liang,Jiang Lu
A facile synthetic route to branched graft copolymers has been developed by combination of self-condensing vinyl polymerization (SCVP), reversible addition–fragmentation chain transfer (RAFT) polymerization and aldehyde–aminooxy reaction. RAFT polymerization of 2-(dimethylamino)ethyl methacrylate (DEM) in the presence of a newly designed aldehyde-containing chain-transfer monomer, 6-(2-formyl-4-vinylphenoxy)hexyl-2-(dodecylthiocarbonothioylthio)-2-methylpropanate (FHDM), led to branched polyDEM (BPDEM) bearing aldehyde functionalities on its branching points. The degree of branching and the average branch length of the resulting BPDEM can be readily tuned by manipulation of the DEM/FHDM feed ratio. The aldehyde groups on the branching points of BPDEM were then reacted with aminooxy-terminated poly(ethylene oxide)s (PEO-ONH2), affording the structurally well-defined branched graft copolymer BPDEM-g-PEO with a branched polyDEM backbone and PEO grafted chains. The thermo-induced micellization behavior of BPDEM-g-PEO in water was investigated. Opportunities are open for BPDEM-g-PEO to form either multimolecular micelles or unimolecular micelles via simply adjusting the chain length of grafted PEO. Further modification of BPDEM-g-PEO by quaternization resulted in branched cationic polyelectrolytes which are capable of capturing negatively charged guest molecules via electrostatic complexation to form in situ self-assembled nanoparticles with simultaneous encapsulation of the guests.
研究领域:
高分子化学
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材料科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING & TECHNOLOGY
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2016
·Vol. 39
·期 10
·1867-1874
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IF 2.385
Jun Mei,Zhirong Chen,Shenfeng Yuan,Jianyong Mao,Haoran Li,Hong Yin
A kinetic study on isophorone synthesis via self-condensation of supercritical acetone catalyzed by aqueous KOH in a tubular flow reactor was conducted. The intention was to improve the isophorone selectivity, with the main approach to reduce the by-products higher-boiling than isophorone. A higher isophorone selectivity was obtained with increased reaction temperature. The structures of main products were determined by gas chromatography-mass spectrometry and nuclear magnetic resonance analysis. The key reaction pathways and a corresponding kinetic model were proposed. The fitted apparent activation energies indicated the reason of isophorone selectivity improvement in that high temperature favors reversion of reversible by-products.
研究领域:
化学工程
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催化反应
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有机化学
✓ 已验证
DOI
高影响因子
ChemCatChem
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2020
·Vol. 13
·期 3
·916-923
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IF 4.853
Qianqian Xu,Xueru Sheng,Haiyuan Jia,Na Li,Jian Zhang,Haiqiang Shi,Meihong Niu,Qingwei Ping
Graphical A heterogeneous catalyst (KOH/diatomite) was prepared in a simple way, and exhibited good activity (overall yield: 85.0 %). We suggest that the excellent catalytic activity of KOH/diatomite can be attributed to the formation of K−O−Si bond, the impurity elements existed in diatomite and higher BET surface areas may also benefit. Aldol condensation of cyclopentanone is an attractive reaction for bio-jet fuel production. KOH is an efficient homogeneous catalyst for aldol condensation but suffering the problem of separation. In this paper, a heterogeneous catalyst, diatomite stabilized KOH (KOH/diatomite) was prepared in a simple way (dry-mixed impregnation process), and exhibited good activity (overall yield: 85.0 %) and reusability. To clarify the support effect of diatomite, KOH/SiO 2 catalyst was also prepared. According to characterizations of these two catalysts, we suggest that the excellent catalytic activity of KOH/diatomite can be attributed to the formation of K−O−Si bond. In addition, the impurity elements existed in diatomite (e. g. CaO, Na 2 O, Al 2 O 3 ) and higher BET surface areas may also benefit to this reaction. This study provides a new possibility for converting homogeneous catalyst (KOH) to heterogeneous catalyst (KOH/diatomite). In this way, KOH/diatomite performed excellent catalytic activity and exhibited stable reusability, which can avoid the problem of separation and pollution.
研究领域:
化学工程
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催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
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2022
·
IF 9.224
Liting Ti,Xueru Sheng,Haiyuan Jia,Qingwei Ping,Ning Li
Self-condensation of biomass-derived cyclopentanone is an attractive reaction for sustainable aviation fuel production. Ball-milling is an effective method for this reaction. However, the effect of process parameters on product yield has not been explored and is still unclear. In this work, the process parameters in the ball-milling process are optimized by orthogonal experiment and subsequently investigated by the response surface methodology. Rotate speed is a critical index for dimer yield, and catalyst dosage is an essential index for trimer yield and selectivity. In addition, a life cycle assessment of both ball-milling and magnetic stirring methods is conducted to reveal the difference between the two methods. The ball-milling method shows relatively excellent economic and environmental potential impact, especially for the toxic consumption of marine aquatic organisms, which is a 38.2% reduction compared to the magnetic stirring method. The ball-milling method introduced in cyclopentanone self-condensation is more sustainable and economical than the magnetic stirring method.
研究领域:
化学工程
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环境科学
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）