Small
·
2023
·Vol. 19
·期 20
·2207821
·
IF 13.3
Zelin Wang,Xidong Lin,Youchen Tang,Dongtian Miao,Junlong Huang,Yan Lu,Shaohong Liu,Ruowen Fu,Dingcai Wu
Carbon-based polymer brushes (CBPBs) are an important class of functional polymer materials, which synergistically combine the advantageous properties of both carbons and polymers. However, the conventional fabrication procedures of CBPBs involve tedious multistep modification, including preoxidation of carbon substrates, introduction of initiating groups, and subsequent graft polymerization. In this study, a simple yet versatile defect-engineering strategy is proposed for the efficient synthesis of high-grafting-density CBPBs with highly stable C C linkages via free radical polymerization. This strategy involves the introduction and removal of nitrogen heteroatoms in the carbon skeletons via a simple temperature-Fmed heat treatment, leading to the formation of numerous carbon defects (e.g., pentagons, heptagons, and octagons) with reactive C=C bonds in the carbon substrates. The as-proposed methodology enables the facile fabrication of CBPBs with various carbon substrates and polymers. More importantly, the highly grafted polymer chains in the resulting CBPBs are tethered with the carbon skeletons by robust C C bonds, which can endure strong acid and alkali environments. These interesting findings will shed new light on the well-orchestrated design of CBPBs and broaden their applications in various areas with fascinating performances.
研究领域:
材料科学
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聚合物化学
·
表面化学
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DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2020
·
IF 16.683
Lixia Li,Juanhua Kong,Huimin Zhang,Sijie Liu,Qiang Zeng,Yaqin Zhang,Hao Ma,Hongyan He,Jinxing Long,Xuehui Li
The catalytic depolymerization process for lignin to produce value added chemicals is often challenged by the limited mass transfer over heterogeneous catalysts, the complex aromatic biopolymer structures, and the high recalcitrance of C C bonds. Herein, a series of hierarchical MFI nanosheets (MFI-ns) supported metal oxide catalysts have been designed and used for the selectively oxidative cleavage of organosolv lignin. As expected, 81.6 % conversion of lignin can be achieved over 15Ce-5Cu/MFI-ns with 294.0 mg g −1 yield of volatile products, including 180.9 mg g −1 of diethyl maleate. Quantum chemistry calculation coupled with static adsorption measurements shows that the superior catalytic activities of these catalysts are ascribed to the favorable mass transport of lignin to the active sites by the unique layer structure, and the hierarchical pore sizes distribution, as well as the electronic effect between Cu and Ce components. In addition, the catalytic mechanism for the cleavage of C C bonds in β -O-4 model probes has been studied via the controlled oxidative degree of model compounds and the isotope-labeling experiments. Therefore, this work provides a new insight into the efficient utilization of lignin via the rational design of catalysts.
研究领域:
化学工程
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材料科学
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催化反应
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产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2017
·
IF 6.844
Huifang Liu,Min Wang,Hongji Li,Nengchao Luo,Shutao Xu,Feng Wang
Catalytic oxidation of C C bond is a key technology to transform petroleum-based as well as sustainable biomass feedstock into more valuable oxygenates. We herein describe a convenient and useful oxidation strategy of converting ketones into carboxylic acids using homogeneous copper catalyst without additives and with O 2 as the terminal oxidant. A wide range of aryl and aliphatic ketones as well as β–O–4 lignin models were selectively oxidized to acids via C C bond cleavage. Mechanism studies by EPR and in situ NMR elucidate the principles of Cu/O 2 reactivity that involves C H bond and O 2 activation via a peroxide species. This provides an important foundation for expanding the scope of useful aerobic oxidation reactions using copper catalysts.
研究领域:
有机化学
·
催化化学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Song Han,Yun Zhao,Mina Liang,Jinshui Su,Xiangxiong Zhai,Qi Zhang,Guoling Li,Zhonghai Ni
The photocatalytic cleavage of C α -C β bonds in lignin holds considerable potential for the production of value-added chemicals. Lignin consists of phenylpropane units interconnected by a variety of complex chemical bonds. Specifically, C-O bonds are more prevalent and relatively easier to cleave, whereas C–C bonds exhibit higher bond energy, rendering them more difficult to cleavage under conventional conditions. This study presents a phosphotungstic acid/phosphoric acid-functionalized porous tubular C 3 N 4 composite photocatalyst (PW/P-TCN). H 3 PO 4 modified PW/P-TCN surfaces enhance O 2 adsorption, improve separation and transfer of photogenerated carriers, and increase exposure of active sites. This promotes reactant adsorption and significantly boosts photocatalytic efficiency. Through this strategy, 1,2-diphenylethanol (DPol), used as a typical model substrate, is fully converted into aromatic monomers, achieving a DPol conversion rate of 99.9 %. Mechanistic studies reveal that C α -C β bond cleavage primarily involves the photo-oxidation mechanism mediated by electron-hole coupling. The construction of the PW/P-TCN heterojunction is essential for simultaneously sustaining robust reduction and oxidation capabilities. Natural lignin samples are applied to the photocatalytic system, and successful C–C bond cleavage depolymerization is achieved under optimal reaction conditions. This study offers valuable insights for the design of more economical and efficient photocatalysts for lignin depolymerization.
研究领域:
材料科学
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环境科学
·
化学工程
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产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2023
·
IF 3.8
Peng Xiong,Tong-Wei Zhang,Shi-Ming Li,Mei-Yu Xu,Guang-Ming -Liang,Liu-Cheng Gui,Xiu-Jian Wang
Two tetranuclear copper cages with tubular type, [Cu 4 (BMBA) 4 ((CH 3 ) 2 N) 2 (H 2 O) 2 ] ( 1 ) and [Cu 4 (BMBA) 4 (Bipy)(H 2 O) 2 ] ( 2 ), were successfully constructed by the reaction of Cu(NO 3 ) 2 with dicarboxylic acid 4,4′-[( ethylazanediyl ) bis ( methylene )]-bis[(1,1′-biphenyl)-2-carboxylic acid] (H 2 BMBA) under solvothermal conditions. The complexes 1 and 2 exhibit a similar cage structure, formed by four ligands connecting two binuclear copper paddle-wheel secondary building units (SBUs). Interestingly, the complex 2 was obtained by appropriately binding of 4, 4′-bipyridine (Bipy) molecule on the axial positions of two Cu paddle-wheels inside the cage. For this reason, the complex 2 exhibits excellent stability in some common organic solvents at room temperature and aqueous solutions with a pH of 2 to 12. Upon thermal activation of complex 2 , the coordinated water molecules can be removed, and its exposed metal active-sites show Lewis acid character, which can be used an efficient heterogeneous catalysis of Knoevenagel condensation (C C) and Clauson-Kaas (C N) reactions.
研究领域:
化学
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材料科学
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催化反应
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DOI
高影响因子
ACS Catalysis
·
2024
·
IF 11.3
Xiaohui Leng,Xin Zhou,Lu Ma,Yonghua Du,Ouwen Peng,Zhongxin Chen,Jinhui Pan,Ming-Yu Qi,Jian-Hui Zheng,Yi-Jun Xu,Kian Ping Loh
Visible light induced oxidative C–C and C–N coupling provides a milder alternative to the current synthetic strategies. However, the photochemical C–C coupling of benzylamine and chromoselective C–C/C–N conversion are not widely reported. Herein, we demonstrate that the introduction of indium vacancies in ZnIn2S4 improves the catalytic activity for C–C coupling of benzylamine and imparts a strong chromoselectivity for C–C or C–N coupled products. A high C–C selectivity of ∼80% is achieved with a benzylamine conversion of ∼80%. Mechanistic studies unveil the switchable reaction routes between kinetically favored C–C coupling and thermodynamically favored C–N coupling under specific illumination conditions.
研究领域:
化学
·
材料科学
·
光催化
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产品关联
DOI
高影响因子
ACS Catalysis
·
2019
·
IF 12.221
Huifang Liu,Hongji Li,Nengchao Luo,Feng Wang
Lignin is the largest carrier of aromatics on earth, and its depolymerization can afford value-added aromatic products. Direct cleavage of the C–C bonds in lignin linkages is significant, but it is challenging to obtain low-molecular-weight aromatic monomers. Herein, using vanadium catalysts under visible light, we selectively cleave the C–C bonds in β-1 and β-O-4 interlinkages occluded in lignin models and extracts by an oxidative protocol. Visible light irradiation triggered single electron transfer between the substrate and the catalyst, which further induced the selective Cα–Cβ bond cleavage and generated the final aromatic products through radical intermediates. Using this photocatalytic chemistry, the reactivity of lignin models and the selectivity of Cα–Cβ bond cleavage were significantly improved. More importantly, this protocol affords aromatic monomers through the fragmentation of organosolv lignins even at room temperature, indicating the potential of photocatalytic C–C bond cleavage of lignin linkages under ambient conditions.
研究领域:
化学
·
环境科学
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产品关联
DOI
高影响因子
ACS Catalysis
·
2021
·
IF 13.084
Yuebing Xu,Wenda Yu,Hao Zhang,Jian Xin,Xiaohui He,Bing Liu,Feng Jiang,Xiaohao Liu
Various Co-based SAPO-34 catalysts were prepared using different methods, including ion exchange (IE), incipient-wetness impregnation (IWI), and solid-phase grinding (SPG), to correlate the chemical states of Co species with the C–H and C–C bond scissions in ethane dehydrogenation. The IE-prepared Co/SAPO-34 led to stable, unreducible, and isolated exchanged Co sites anchored on the zeolite framework with a structure of −AlF–O–Co–O– and showed the highest selectivity to ethylene of close to 98% at 600 °C, which suggests that these Co sites favors suppressing the C–C bond scission in ethane. In comparison, the IWI- and SPG-prepared Co/SAPO-34 catalysts, especially for those with a high Co loading, inevitably give Co oxide clusters that are easily reduced into metallic Co. Together with catalytic results, characterizations, and DFT calculations, it is confirmed that the reduced Co clusters, especially for those outside SAPO-34 channels without the confinement effect, favor both C–H and C–C bond scission, boosting the conversion of ethane into CH4 or/and coke; however, the ionic-state −Co–O– species can smoothly terminate the ethane dehydrogenation for the ethylene product due to relatively high energy barriers for both C–H and C–C bond scission, avoiding a deep dehydrogenation and C–C cracking. As expected, the unreducible −Co–O– sites are very stable in the title reaction without deanchoring from the zeolite framework in a 100 h cyclic test. This study not only demonstrates the stable −Mδ+–Oδ− structure favorable for suppressing C–C bond scission but also highlights a catalyst-constructing strategy for Co-based and similar metal-based catalysts for dehydrogenation of other light alkanes.
研究领域:
催化化学
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材料科学
·
计算化学
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产品关联
DOI
高影响因子
Molecular Catalysis
·
2025
·
IF 4.9
Wei Wang,Rui Zhang,Jiaqing Li,Huai Liu,Wenlong Jia,Junhua Zhang,Dan Li,Lincai Peng
Furans are important scaffolds with applications in pharmaceuticals, polymers synthesis and biofuels. The direct production of new types of furans from glucose is therefore significant but remains a great challenge. Herein, we report a facile strategy to produce acetylfurans directly from glucose over MoCs-SiO 2 , with an increase in yield from 35.8 % to 81.4 % compared with pristine Mo-SiO 2 due to the facilitated C−C bond cleavage of glucose. The incorporation of Cs improved the dispersion of Mo species, induced the formation of partially reduced Mo, increased the Lewis acidity and glucose adsorption of the catalyst, and thus shifting the reaction selectivity from C−C coupling to cleavage. Kinetic studies further demonstrated the positive contribution of Cs as a promoter in lowering the activation energy of C−C bond cleavage. This study provides a promising strategy to broaden the range of furanic compounds derived from glucose for product-oriented biorefineries.
研究领域:
化学工程
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生物催化
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可再生资源利用
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产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Xiaotong Yang,Kaiyu Dong,Zhe Zheng,Yuehuan Zhang,Qiang Yuan
Efficient C C bond cleavage and the complete oxidation of alcohols are key to improving the efficiency of renewable energy utilization. Herein, we successfully prepare porous Fe-doped hexagonal close-packed ( hcp )-PtBi/face-centered cubic ( fcc )-Pt heterostructured nanoplates with abundant grain/phase interfaces ( h -PtBi/ f -Pt@Fe 1.7 PNPs) via a simple solvothermal method. The open porous structure, abundant grain/phase interface and stacking fault defects, and the synergistic effect between intermetallic hcp -PtBi and fcc -Pt make h -PtBi/ f -Pt@Fe 1.7 PNPs an effective electrocatalyst for the glycerol oxidation reaction (GOR) in direct glycerol fuel cells (DGFCs). Notably, the h -PtBi/ f -Pt@Fe 1.7 PNPs exhibit an excellent mass activity of 7.6 A mg Pt −1 for GOR, 4.75-fold higher than that of commercial Pt black in an alkaline medium. Moreover, the h -PtBi/ f -Pt@Fe 1.7 PNPs achieve higher power density (125.8 mW cm −2 ) than commercial Pt/C (81.8 mW cm −2 ) in a single DGFC. The h -PtBi/ f -Pt@Fe 1.7 PNPs can also effectively catalyze the electrochemical oxidation of 1-propanol (17.1 A mg Pt −1 ), 1,2-propanediol (7.2 A mg Pt −1 ), and 1,3-propanediol (5.2 A mg Pt −1 ). The in-situ Fourier-transform infrared spectra further reveal that the C C bond of glycerol, 1-propanol, 1,2-propanediol, and 1,3-propanediol was dissociated for the complete oxidation by the h -PtBi/ f -Pt@Fe 1.7 PNPs. This study provides a new class of porous Pt-based heterostructure nanoplates and insight into the intrinsic activity of different C3 alcohols.
研究领域:
材料科学
·
能源化学
·
电化学
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产品关联
DOI
PubMed
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2018
·Vol. 20
·期 26
·17942-17951
·
IF 3.906
Muge Niu,Yucui Hou,Weize Wu,Shuhang Ren,Ru Yang
Vanadium(V)-catalyzed aerobic oxidation in aqueous solution shows high selectivity in the field of C–C bond cleavage of carbohydrates for chemicals with less carbon atoms. However, the pathway of C–C bond cleavage from carbohydrates and the conversion mechanism are unclear. In this work, we studied the pathway and the mechanism of D-glucose oxidation to formic acid (FA) in NaVO3–H2SO4 aqueous solution using isotope-labeled glucoses as substrates. D-Glucose is first transformed to FA and D-arabinose via C1–C2 bond cleavage. D-Arabinose undergoes similar C1–C2 bond cleavage to form FA and the corresponding D-erythrose, which can be further degraded by C1–C2 bond cleavage. Dimerization and aldol condensation between carbohydrates can also proceed to make the reaction a much more complicated mixture. However, the fundamental reaction, C1–C2 bond cleavage, can drive all the intermediates to form the common product FA. Based on the detected intermediates, isotope-labelling experiments, the kinetic isotope effect study and kinetic analysis, this mechanism is proposed. D-Glucose first reacts with a vanadium(V) species to form a five-membered-ring complex. Then, electron transfer occurs and the C1–C2 bond weakens, followed by C1–C2 bond cleavage (with no C–H bond cleavage), to generate the H3COO˙–vanadium(IV) complex and D-arabinose. FA is generated from H3COO˙ that is oxidized by another vanadium(V) species. The reduced vanadium species is oxidized by O2 to regenerate to its oxidation state. This finding will provide a deeper insight into the process of C–C bond cleavage of carbohydrates for chemical synthesis and provide guidance for screening and synthesizing new highly-efficient catalyst systems for FA production.
研究领域:
化学
·
生物化学
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产品关联
DOI
PubMed
高影响因子
Nature Communications
·
2021
·Vol. 12
·期 1
·1-12
·
IF 14.919
Xie Chao,Lin Longfei,Huang Liang,Wang Zixin,Jiang Zhiwei,Zhang Zehui,Han Buxing
Selective cleavage of C-C bonds is very important in organic chemistry, but remains challenging because of their inert chemical nature. Herein, we report that Zn/NC-X catalysts, in which Zn 2+ coordinate with N species on microporous N-doped carbon (NC) and X denotes the pyrolysis temperature, can effectively catalyze aerobic oxidative cleavage of C(CO)-C bonds and quantitatively convert acetophenone to methyl benzoate with a yield of 99% at 100 °C. The Zn/NC-950 can be applied for a wide scope of acetophenone derivatives as well as more challenging alkyl ketones. Detail mechanistic investigations reveal that the catalytic performance of Zn/NC-950 can be attributed to the coordination between Zn 2+ and N species to change the electronic state of the metal, synergetic effect of the Zn single sites with their surrounding N atoms, as well as the microporous structure with the high surface area and structural defects of the NC.
研究领域:
有机化学
·
催化材料科学
✓ 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）