GREEN CHEMISTRY
·
2020
·Vol. 22
·期 8
·2468-2473
·
IF 9.48
Taimei Cai,Qiang Deng,Hailong Peng,Jin Zhong,Rui Gao,Jun Wang,Zheling Zeng,Ji-Jun Zou,Shuguang Deng
The major challenge in the synthesis of high-density biofuels is to identify the bio-based source for C–C cyclic compounds and C–C coupling reactions with a suitable selectivity. Herein, we selectively synthesize 1,2,4-benzenetriol (BTO) with a yield of 51.4% from cellulose-derived 5-hydromethylfurfural via a ring-rearrangement reaction. The cellulose-derived route is a more meaningful route for the C–C cyclic compounds compared to the traditional hemicellulose- and lignin-derived routes. Furthermore, BTO is very easily dimerized via a C–C oxidative coupling reaction, showing a yield of 94.4% and selectivity of nearly 100% under environmentally friendly reaction conditions. After hydrodeoxygenation, bicyclohexane is obtained with a yield of 87.4%. This work not only provides a promising route to produce C–C cyclic fine compounds based on a cellulose-derived route, but also shows a highly efficient synthesis route for high-density biofuels via the C–C oxidative coupling reaction.
研究领域:
化学工程
·
可再生能源
·
合成化学
✓ 已验证
产品关联
DOI
高影响因子
BIOMASS & BIOENERGY
·
2022
·
IF 5.774
Jie Zhang,Danyang Cao,Shanshan Wang,Xin Feng,Jiahua Zhu,Xiaohua Lu,Liwen Mu
In this study, heteroelement-rich groups (N and B elements, tris (2-hydrazinylethyl) borate) were successfully synthesised on lignin by microwave amination. The reaction between lignin and heteroelement-rich groups was confirmed using several characterization techniques, including fourier transform infrared (FT-IR) spectroscopy, thermogravimetric (TG) analysis, and X-ray photoelectron spectroscopy (XPS). A lignin model compound (2-phenoxyacetophenone (L-M)) was used to study the bond-breaking mechanism of lignin depolymerization , and the amine group, which acted as a nucleophile , attacked the C–C bond to form an amide bond with the lignin. As an effective additive, modified lignin can increase the viscosity of poly (ethylene glycol) 200 (PEG200), reducing the wear volume and friction coefficient in the friction test. Theoretical calculations showed that the polarity of the modified lignin increased, which allowed the modified lignin to form a strong physical adsorption on the metal surface. In addition, the reciprocal hydrogen bonding between the modified lignin and PEG200 contributes synergistically to the enhanced lubrication film strength , and thus, the better tribological properties of these new lubricants.
研究领域:
高分子化学
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材料科学
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绿色化学
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表面工程
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能源材料
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可持续技术
✓ 已验证
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2024
·
IF 5.6
Zhen Huang,Penghao Sun,He Liu,Chunyu Ren,Xiangyu Lin,Minggui Shen,Zhaoshuang Li,Xu Xu
To obtain high-valued aromatic products, it is paramount to cleave the C α −C β bonds in lignin under mild conditions selectively. Nevertheless, this task remains daunting due to the formidable dissociation energies and steric hindrance associated with these bonds. Herein, a facile, efficient and cost-effective strategy for selectively breaking the C α −C β bond in lignin with visible-light irradiation and room temperature is proposed, facilitated by the utilization of the ferric-doped mesoporous graphitic carbon nitride (Fe/mpg-CN) photocatalyst. Collective contributed by the reduced band gap and photoluminescence, combined with intensified visible-light absorption and enhanced photocurrent, the effectiveness in photocatalytic activity of Fe/mpg-CN is offered. Specifically, a high conversion rate (98 %) of the lignin model compound (2-phenoxy-1-phenylethanol), coupled with an excellent selectivity of 98 % in cleaving the C α −C β bonds is achieved by Fe/mpg-CN. Photogenerated holes are indicated as the main active species through comprehensive mechanistic investigations. Additionally, the successful photocatalytic depolymerization of the complex dimer model compound (conversion rate ∼ 96 %) and pine kraft lignin further corroborate the satisfying photocatalytic activity and selectivity of Fe/mpg-CN. This study introduces a promising and viable strategy for the selective breaking of lignin through photocatalysis, offering significant implications for the sustainable production of valuable aromatic compounds.
研究领域:
化学工程
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环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 51
·26804-26809
·
IF 3.708
Liang Ren,Fan Yang,Yongfeng Li,Ting Liu,Liqiang Zhang,Guoqing Ning,Zhichang Liu,Jinsen Gao,Chunming Xu
We report an environmentally-friendly approach to the synthesis of hybrids based on porous graphene and metal nanoparticles. The nitrogen-doped porous graphene (N-PG) and Pd nanoparticles decorated N-PG (Pd/N-PG) was synthesized by a plasma method. The N-PG was characterized by X-ray photoelectron spectroscopy and Raman spectroscopy, and the results clearly indicate that the amount of nitrogen doping was 6.65 wt%. The synthesized Pd/N-PG hybrid materials were confirmed by transmission electron microscopy, X-ray diffraction and energy-dispersive X-ray spectroscopy mapping. The hybrid material based on Pd/N-PG as a new catalyst was applied in Suzuki reaction. This catalyst offers a number of advantages such as high stability, easy removal from the reaction mixture and reusability with minimal loss of activity, showing better performance than the well-known commercial Pd/C catalyst.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS & DESIGN
·
2018
·
IF 4.525
Haibo Ouyang,Guibiao Li,Cuiyan Li,Jianfeng Huang,Jie Fei,Jing Lu
C/C-Zr-Si-O composites were prepared by carbothermal reduction of hydrothermal co-deposited ZrO 2 , SiO 2 , and C. The bulk density of composites reached 1.71 g/cm 3 with 8 cycles of co-deposition. The matrix of the composites includes ZrC, SiC, ZrO 2 , and SiO 2 with fine grain size (300–500 nm) and homogeneous distribution. The mass and linear ablation rate of C/C-Zr-Si-O composites were 0.112 mg/cm 2 ·s and 0.46 μm/s, respectively, under a plasma flame for 120 s. The attractive ablation resistance of the composites resulted from its unique structure, which tends to form a continuous ZrO 2 -SiO 2 glass layer in the ablation center, a layer of SiO 2 -ZrO 2 bubbles in the transition region, and fluffy SiO 2 nanowires layer in the heat-affected region. These ablation layers were barriers to restrain the diffusion of oxidative gas and heat. The C/C-Zr-Si-O composites provide an alternative ceramics system with attractive ablation resistance, while carbothermal reduction of hydrothermal co-deposited oxides is a feasible method for the structural design of carbon fiber reinforced ultra-high temperature ceramic.
研究领域:
材料科学
·
航空航天工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Yun Tang,Jingqi Ruan,Yalou Xin,Xiaohu Ren,Hudie Yuan,Xianhu Liu,Qiang Chen
The development of metal–organic frameworks (MOFs)-derived magnetic carbon-based materials for high-efficiency electromagnetic wave (EMW) absorption has attracted widespread attention. While these MOFs-derived composites have shown exceptional performance in absorbing EMWs within the X and Ku bands, the pursuit of effective absorption at lower frequencies remains a challenge. Herein, we demonstrate a novel strategy to synthesize hollow Co@C/C rods with excellent C-band EMW absorption via acetic acid etching and pyrolysis of core–shell ZIF-8@ZIF-67. Based on acetic acid etching, ligand-deficient ZIF-8@ZIF-67 rods with abundant mesoporous structures are constructed, enabling precise control over the Co nanoparticles content, graphitization degree, and pyridinic N doping in the derived Co@C/C. This simple fine-tuning approach simultaneously reduces dipole polarization by lowering the pyridinic N doping concentration, suppresses interfacial polarization and conduction loss through reducing the number of graphitic carbon layer, and enhances magnetic loss by increasing the Co content. These combined effects collectively improve the impedance matching of Co@C/C for low-frequency absorption. Notably, as the volume of acetic acid solution increases, the absorption frequency band of Co@C/C gradually shifts from the Ku-band to the C-band, while sustaining superior EMW absorption performance. At the filling ratio of merely 11 %, the RL min values for Co@C/C-20 and Co@C/C-30 achieve −49.8 dB and −34.7 dB at 7.2 GHz and 6.8 GHz, respectively. This study offers a valuable approach to the development of lightweight materials with excellent EMW absorption in C-band.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
ChemNanoMat
·
2021
·Vol. 7
·期 10
·1131-1137
·
IF 3.154
Panpan Chang,Fan Yang,Yongbing Cen,Jie Zheng,Xuguang Li,Qingruo Xie,Jinshi Dong
Graphical A hierarchical nanoporous C/C composite with high specific surface area was synthesized from sulfonated pitch and fulvic acid for high-energy-density EDLCs. It exhibits a highly continuous 3D carbonaceous network. By fully exploiting the synergistic effect between high e -conductivity and high specific surface area, it shows excellent electrochemical stability in EMIMBF 4 ionic liquid electrolyte. The maximum energy density can be as high as 55.4 Wh kg −1 , largely better than commercial activated carbon. As a new type of energy storage device, electric double layer capacitors (EDLCs) possess fast charge/discharge speed and good cycling stability. However, the low energy density and high production cost of EDLC electrodes are still big challenges. Herein, a hierarchical nanoporous C/C composite is synthesized by chemical recombination and subsequent activation strategy from low-cost carbon resources, namely renewable humic fulvic acid (FA) and industrial sulfonated pitch (SP). Profiting from the abundant polycyclic aromatic hydrocarbons in SP and plentiful oxygen-containing groups in FA, the resultant nanoporous C/C composite has both high e -conductivity and high specific surface area (SSA). Thus, this porous C/C composite can be directly fabricated as EDLC electrode without any conductive agent. By fully exploiting the synergistic effect between high e -conductivity and high SSA, it shows excellent electrochemical stability in EMIMBF 4 ionic liquid electrolyte. Furthermore, it possesses a higher specific gravimetric capacitance (117 F g −1 ) than that of pure FA-based porous carbon (92.5 F g −1 ) at a current density of 1 A g −1 . More importantly, the maximum energy density can be as high as 55.4 Wh kg −1 , largely better than commercial activated carbon.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2023
·Vol. 17
·期 6
·772-783
·
IF 4.5
Gao Xiu,Luo Beining,Hong Yanping,He Peihang,Zhang Zedong,Wu Guoqiang
Development of a titanium silicalite-1 (TS-1) catalyst with good crystallinity and a four-coordinate Ti framework is critical for efficient catalytic oxidation reaction under mild conditions. Herein, a size-controlled TS-1 zeolite (TS-1#0.1ACh (acetylcholine)) was synthesized via steam-assisted crystallization by introducing acetylcholine as a crystal growth modifier in the preparation process, and TS-1#0.1ACh was also employed in epoxidations of different substrates containing C=C double bonds. The crystalline sizes of the as-synthesized TS-1#0.1ACh catalysts were controlled with the acetylcholine content, and characterization results showed that the particle sizes of highly crystalline TS-1#0.1ACh zeolite reached 3.0 µm with a good Ti framework. Throughout the synthetic process, the growth rate of the crystals was accelerated by electrostatic interactions between the connected hydroxyl groups of the acetylcholine modifier and the negatively charged skeleton of the pre-zeolites. Furthermore, the TS-1#0.1ACh catalyst demonstrated maximum catalytic activity, good selectivity and high stability during epoxidation of allyl chloride. Importantly, the TS-1#0.1ACh catalyst was also highly versatile and effective with different unsaturated substrates. These findings may provide novel, easily separable and large TS-1 catalysts for efficient and clean industrial epoxidations of C=C double bonds.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
ACS Catalysis
·
2018
·
IF 11.384
Huifang Liu,Hongji Li,Jianmin Lu,Shu Zeng,Min Wang,Nengchao Luo,Shutao Xu,Feng Wang
Photocatalysis is a potentially promising approach to harvest aromatic compounds from lignin. However, the development of an active and selective solid photocatalyst is still challenging for lignin transformation under ambient conditions. We herein report a mild photocatalytic oxidative strategy for C–C bond cleavage of lignin β-O-4 and β-1 linkages using a mesoporous graphitic carbon nitride catalyst. Identifications by solid-state NMR techniques and density functional theory (DFT) calculations indicate that π–π stacking interactions are most likely present between the flexible carbon nitride surface and lignin model molecule. Besides, low charge recombination efficiency and high specific surface area (206.5 m2 g–1) of the catalyst also contribute to its high catalytic activity. Mechanistic investigations reveal that photogenerated holes, as the main active species, trigger the oxidation and C–C bond cleavage of lignin models. This study sheds light on the interaction between complex lignin structures and the catalyst surface and provides a new strategy of photocatalytic cleavage of lignin models with heterogeneous photocatalysts.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CORROSION SCIENCE
·
2015
·
IF 4.422
Dong Huang,Mingyu Zhang,Qizhong Huang,Liping Wang,Liang Xue,Xian Tang,Kejian He
C/C–ZrB 2 –ZrC–SiC composites were fabricated by polymer infiltration and pyrolysis (PIP) with a preform of C f /ZrB 2 . The ZrB 2 powders were sprayed onto fabric layer by layer before the fabric is needled. After introduction of resin carbon and ZrC–SiC into the preform, a ceramic coating on the matrix and fibres was formed in the composites. The plasma ablation test indicates that the composites possess a good ablation resistance after ablation for 180 s and 240 s. The SiO 2 –ZrO 2 barrier layer, high temperature Zr–Si–O glass layer and heat dissipation all contribute to the good ablation resistance of the composites.
研究领域:
材料科学
·
航空航天工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Rui Li,Qixuan Lin,Yingxiong Wang,Weiran Yang,Xinxin Liu,Weiying Li,Xiaohui Wang,Xiaoying Wang,Chuanfu Liu,Junli Ren
The efficient production of xylose and arabinose from glucose, is significant but technologically challenging. Herein, the conversion of glucose to pentose (xylose and arabinose) and formic acid was realized using non-toxic artificial zeolite and green solvent of γ-butyrolactone-H 2 O. The selective conversion of glucose to 5-hydroxymethylfurfural, pentose and furfural could be regulated by controlling Brønsted acid strength. The weak Brønsted acid could promote the formation of pentose, while strong Brønsted acid could lead to the formation of HMF and further degradation of pentose to furfural. The mechanism was investigated spectroscopically to add fundamental insights to the selective C1-C2 bond cleavage. The solvent of γ-butyrolactone-H 2 O reduced apparent activation energy by promoting the formation of active d -fructofuranose. The favorable yield reached to 54.3 % pentose and 54.7 % formic acid from glucose, while 95.6 % pentose and 96.8 % formic acid from fructose at 453 K for 1.5 h. This strategy offered a new utilization way of glucose in expanding the varieties of platform chemicals.
研究领域:
化学工程
·
催化
·
绿色化学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2023
·
IF 7.3
Jin Yuan,Zhiwei He,Hongbo Zhang
Selective C–H bond oxidation of cyclohexane into KA oil (ketone-alcohol) is of vital importance in both fundamental research and industrial applications while limited by complex reaction network and suffering from low efficiency. In this study, Ce(OH)SO 4 · x H 2 O was chosen as a probe to systematically investigate the C–H bond activation and C–C bond rupture as a function of various reaction parameters, including the reactant/product concentrations, catalyst applied, reaction temperatures, acidic concentrations etc, and found that bi-molecule of C 6 H 12 was probably involved in both C–H bond rupture and C–C bond cleavage and both were controlled by one deprotonation elementary step with ·O 2 – and h + as the key active components, which were supported by parity fittings and primary KIEs determined. In addition, the C–C bond rupture was found to be mainly following C 6 H 10 O to ε-caprolactone and further to linear acids reaction path. Hopefully, this study could help people find/optimize reaction systems in selective hydrocarbon upgradings.
研究领域:
化学工程
·
有机化学
·
催化
✓ 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）