Journal of Energy Chemistry
·
2022
·
IF 13.599
Shuang Xiang,Lin Dong,Zhiqiang Wang,Xue Han,Yong Guo,Xiaohui Liu,Xue-Qing Gong,Yanqin Wang
The depolymerization and upgrading of lignin from raw biomass, while keeping cellulose intact is important in biorefinery and various metal-based catalysts have been used in reductive catalytic fractionation, a key method in “lignin-first” strategy. Recently, we found that a core–shell structured Co@CoO catalyst with CoO shell as the real active site had excellent performance in the hydrogenolysis of 5-hydromethylfurfural to 2,5-dimethylfuran due to its unique ability to dissociate H 2 and yield active H δ− species (Xiang et al., 2022). In this work, we report a one-pot depolymerization and upgrading of lignocellulose to alkylcyclohexanols, a flavour precursor, with intact cellulose over this unique core–shell structured catalyst, Co@CoO. Lignin model compounds (β-O-4, 4-O-5, α-O-4) were first used to clarify the activity of Co@CoO catalyst. Then, the one-pot conversion of various organosolv lignin (birch, pine and poplar) to alkylcyclohexanols was realized with the mass yield of alkylcyclohexanols up to 25.8 wt% from birch lignin under the reaction condition of 210 °C, 1 MPa H 2 , 16 h. Finally, the corresponding woody sawdusts were used as feedstocks and found that the Co@CoO catalyst indeed preferentially depolymerized and upgraded the lignin part and obtained the same alkylcyclohexanols products with the retention of cellulose-rich pulp. The collected alkylcyclohexanols were further esterified to obtain value-added esters, which can be used as flavors. This work will inspire the design of new efficient metal oxide catalysts in lignin fractionation and depolymerization to high-value-added chemicals with intact cellulose.
研究领域:
生物化学
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催化化学
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可再生资源利用
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Minglong Yang,Ye Yuan,Weilong Yin,Shuang Yang,Qingyu Peng,Jianjun Li,Yibin Li,Xiaodong He
High performance broadband microwave absorption material is in urgent demand as the radar detection frequency range has been greatly broadened and electromagnetic radiation pollution has become increasingly serious. In this work, we fabricated a hierarchical bowknot-like Co/CoO@C nanocomposite with a two-step hydrothermal method, followed by high-temperature pyrolysis under argon atmosphere, which is composed of amorphous carbon and uniformly dispersed irregular Co/CoO nanoparticles. Complex permittivity and complex permeability were modulated by varying the calcination temperature (500–700 °C). Reflection loss (RL) curves of the Co/CoO@C nanocomposites show superior broadband electromagnetic wave absorption performance. Especially, the effective absorption bandwidth was maximized to 13.6 GHz (4.4–18 GHz) at the thickness of 6 mm, and a −45.0 dB minimum RL appears at 6 GHz. Such superior broadband electromagnetic wave absorption properties are attributed to the synergistic effect of the hierarchical bowknot-like structure and strong surface/interface polarization, as well as the eddy current and magnetic natural resonance. These results indicate the bowknot-like Co/CoO@C nanocomposite is promising in dealing with broadband electromagnetic radiation pollution and broadband military radar detection.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Xiaoming Fan,Yuyin Fan,Xiao Zhang,Lin Tang,Jinxue Guo
Heterostructured materials favoring synergism, efficient charge transfer, and abundant active sites have aroused enormous interests for water electrolysis. Here heterogeneous Co@CoO encapsulated in P, N co-doped carbon nanofibers supported on carbon cloth (Co@CoO-PNC/CC) has been prepared to pursue attractive synergism for the application of pH-tolerant catalyst for oxygen evolution reaction (OER) in both alkaline and neutral solutions. The prepared Co@CoO-PNC/CC exhibits advanced OER performances, generating a current density of 10 mA cm −2 at overpotential of 289 mV in alkaline media and 371 mV in neutral media. The high OER activity can be assigned to the synergistic effect of abundant active sites and enhanced charge transfer between Co and CoO, as well as the specific P, N co-doped carbon nanofiber architecture.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2023
·
IF 16.5
Wanjun Guo,Zhi-Qiang Wang,Shuang Xiang,Yaxuan Jing,Xiaohui Liu,Yong Guo,Xue-Qing Gong,Yanqin Wang
ABSTRACT Owing to the wide application of primary amines, their selective production via reductive amination has become a crucial research topic. Various metal-supported catalysts (Pt, Ru, Rh, Ir, Co, Ni, etc. ) have been investigated, and metallic species have been recognized as active sites in recent years. Herein, we reveal for the first time that CoO species containing oxygen vacancies within a core-shell-structured Co@CoO catalyst accelerate the ammonolysis of Schiff bases, key intermediates in reductive amination, through NH 3 dissociation to hydride-like NH 2 δ – species, delivering an excellent reductive amination performance. The catalyst is highly stable and was utilized in 10 catalytic cycles for the amination of biomass-derived cyclopentanone (CPO) to cyclopentylamine (CPA) without deactivation. Various computational models in combination with spectroscopic measurements indicated that this catalyst not only drives the dissociation of H 2 to the active H δ – species, but also enables the homolytic cleavage of NH 3 to NH 2 δ – . D 2 isotopic tracing experiments provided further evidence of the direct involvement of hydride-like NH 2 δ – species in Schiff base ammonolysis. Theoretical calculations verified the stable co-adsorption of H δ – and NH 2 δ – , which allows the Schiff base to move freely on the surface of the CoO shell and participate extensively in molecular collisions, resulting in exceptional catalytic activity. This is the first study that demonstrates the potential of metal oxide catalysts for the production of primary amines via reductive amination.
研究领域:
催化
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化学工程
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材料科学
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物理化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2017
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IF 3.133
Jie Yu,Yonghong Ni,Muheng Zhai
Co-based compounds, especially cobalt oxides, have been widely employed as the non-enzyme catalysts for the electro-oxidation of glucose. In this work, we designed a solution-combustion and subsequent heat-treating route to successfully prepare Co-CoO-Co 3 O 4 nanocomposites. Co-CoO nanocomposites were first obtained in one step via a simple solution-combustion method, employing CoCl 2 as the Co source, oxygen in air as the oxygen source, and ethanol as the solvent and fuel; and then, the freshly-prepared Co-CoO nanocomposites were annealed in air at 300–600 °C for 2 h. Experiments showed that the annealing temperature strongly affected the component of the final product. Co-CoO-Co 3 O 4 nanocomposites were produced at 300 and 400 °C; CoO-Co 3 O 4 nanocomposites were obtained at 500 °C; and Co 3 O 4 nanoparticles were formed at 600 °C. The above annealed products were labeled as T3, T4, T5 and T6. Electrochemical measurements showed that Co-CoO nanocomposite and its annealed products presented good electrochemical properties and could be employed as catalysts for the non-enzyme electro-oxidation of glucose. Among them, T4 sample (Co-CoO-Co 3 O 4 nanocomposites) possessed the best electrocatalytic activity. The as-prepared T4/GCE sensor showed rapid response time (<1s), high sensitivity (949.3 μA mM −1 cm −2 ), long linear range (0.005–0.6, 0.6–4.3 mM), low detection limit (0.92 μM), and good stability and selectivity.
研究领域:
材料科学
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分析化学
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生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 31
·15071-15079
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IF 3.925
Li Yan,Dandan Chu,Xue-Qiang Chu,Danhua Ge,Xiaojun Chen
Glucose determination with high sensitivity is crucial in human serum and food products. Herein, Co/CoO nanoparticles attached on the outer shell and inner core of porous N-doped carbon polyhedrons (Co/CoO/N-C) were successfully prepared from zeolite imidazole frameworks (ZIF-67) via a pyrolysis–reorganization method, and their sensing performances towards glucose oxidation were demonstrated. For comparison, the ZIF-67, Co3O4 and the sample from ZIF-67@PDA were also tested. Moreover, the experimental results indicated that the Co/CoO/N-C sensor exhibited enhanced electrochemical performance for glucose oxidation, such as high sensitivity (143.9 μA mM−1 cm−2), a wide linear detection range (0.01–16.65 mM) and a low detection limit (0.8 μM, S/N = 3), as well as satisfactory stability and reproducibility. Furthermore, the proposed sensor presented feasibility in real samples. This study may offer a possible way to design and develop MOF-derived electrocatalysts for disease diagnosis and food quality control.
研究领域:
材料科学
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电化学
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传感器
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分析化学
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 32
·15712-15722
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IF 3.925
Wen Xu,Yuan Ma,Xinjia Wei,Honghui Gong,Xiuge Zhao,Yuxi Qin,Qingpo Peng,Zhenshan Hou
A new strategy has been proposed for synthesizing Co@CoO core–shell nanoparticles with a core–shell structure, which involves a facile solvent-thermal process in deep eutectic solvents (DESs). In contrast to the irregular sheet-like packing material obtained in water, twinned and 3D-ellipsoid-shaped nanoparticles were achieved in choline chloride (ChCl)/glycerol and ChCl/PEG-300, respectively. It was found that the nanoparticles were featured as metal Co(0) cores homogeneously wrapped by CoO shells after reduction under a H2 atmosphere. The Co@CoO core–shell nanoparticles showed good activity and stability for the hydroformylation of olefins, and the conversion of 1-octene can reach 99% at 130 °C under 4 MPa (CO/H2 = 1) pressure, and the selectivity to C9 aldehydes was reached up to 97%. The characterization by XPS, H2-TPR and HRTEM indicated that metal Co(0) species could be an active site for hydroformylation of olefins. Notably, the leaching of cobalt carbonyl species was highly dependent on the surface molar ratio of Co2+/Co0 as revealed by XPS spectra, and the surface CoO layer played an important role in suppressing the loss of active Co species in hydroformylation of olefins. Moreover, the core–shell nano-catalysts are easily separated magnetically from the reaction mixture and showed good recyclability in nine consecutive catalytic runs.
研究领域:
催化化学
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材料科学
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表面化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2025
·
IF 7.9
Xin Miao,Yunxin Shi,Liying Wang,Zhenzhu Cao,Yongfeng Zhang,Shaohua Luo
Hollow Co/CoO@NSCO nanospheres were synthesized via solvothermal derivation from dual-ligand Co-MOF, followed by controlled calcination. The calcination-temperature-mediated tuning of Co/CoO ratios and oxygen vacancy concentrations significantly enhanced lithium storage performance. Optimized Co-450 (450 °C calcination) delivered exceptional reversible capacities of 1112.5 mAh g −1 at 0.2 A g −1 after 100 cycles and 605.6 mAh g −1 at 1 A g −1 after 1000 cycles. Ex situ XRD confirmed metallic Co's role as an electrochemically inactive conductive matrix, while oxygen vacancies (65.7 % by XPS) facilitated rapid Li + diffusion. Kinetic analysis revealed hybrid charge storage: capacitive effects (68 % contribution at 1 mV s −1 ) dominated by pseudocapacitance from Co 2+ /Co 3+ redox couples, complemented by diffusion-controlled processes. The hierarchical hollow structure accommodated volume changes, and heteroatom-doped carbon enhanced electronic conductivity. This work demonstrates calcination-driven phase engineering as a viable strategy for high-performance anodes.
研究领域:
材料科学
·
电化学
·
纳米技术
·
储能
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2026
·Vol. 16
·期 16
·16105-16114
·
IF 13.6
Li Tan,Meng Yang,Sun Bingyan,Shi Xiaopeng,Su Jing,Wang Keran,Wang Kaige
Elucidating the role of hydrogen spillover in regulating the active sites of metal-acid catalysts is essential to enable selective lignin hydrodeoxygenation toward aviation biofuels. Herein, we developed a MoO 3 /Co@CoO catalyst that enables efficient hydrodeoxygenation of lignin and its derivatives into aviation biofuels. The catalyst achieved nearly complete conversion of monomeric phenolic derivatives with ∼99% selectivity toward aviation-range hydrocarbons, while lignin afforded 16.3 wt % liquid hydrocarbons with 53.2% selectivity to aviation-range hydrocarbons under mild conditions. Structural analyses confirmed the formation of a Co@CoO core−shell architecture and Co−O−Mo interfacial bonding. Combined experimental and DFT studies revealed that Co 0 sites facilitate H 2 dissociation, whereas the Co−O−Mo interface enables accelerated hydrogen spillover from Co to Mo species, generating Brønsted acid sites (Mo−OH) and driving the selective formation of aviation biofuel components. This work offers fundamental insights into rationally controlling hydrogen spillover via interface engineering in metal-acid catalysts for lignin hydrodeoxygenation.
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Yuchen Zhang,Yongqian Shen,Minmin Dang,Fan Zhang,Xueyan Du
Carbon nanofiber composites could be used as a microwave absorbing candidate owing to its lightweight and dielectric properties . In this work, the carbon-based nanofibers were synthesized using cobalt acetate tetrahydrate (CoAc)/poly (vinyl alcohol) (PVA) as a precursor solution via the electrospinning and vacuum carbonization at 650 °C. Co and CoO were simultaneously introduced into carbon nanofibers (CNFs). The CNFs absorber with an especially low filling ratio of 10% exhibited excellent microwave absorbing properties. The minimum reflection loss (RL) reached −43.57 dB at 10.48 GHz with a matching thickness of 3 mm, and the wideband effective absorption (RL ≤ −10 dB) reached 5.78 GHz (10.94–16.72 GHz) at 2.5 mm. The superior absorption performance of the as-prepared CNFs resulted from the formation of CoO, causing the improvement of impedance matching and interfacial polarization. Besides, the CNFs displayed good hydrophobicity due to the roughened surfaces. These newly synthesized Co/CoO/CNFs might be considered as a prospective candidate for highly efficient microwave absorption materials with a self-cleaning function.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2017
·
IF 9.446
Zheng Wan,Qian Xu,Hui Li,Yi Zhang,Yong Ding,Jide Wang
This paper introduces the first attempt of using well organized Co@CoO core-shell nanocrystals as an alternative toward noble metal catalysts for photocatalytic water splitting reactions. In this work, four kinds of stable magnetic Co@CoO core-shell nanocrystals were fabricated through a one-pot toluene-water two-phase interfacial reaction with oleic acid as a surfactant. The size and shape of the as-prepared crystals can be carefully adjusted through dynamically coating the closely packed monolayer of coordinating ligand onto the growing crystals. It is notable that spherical pine-nut-like hierarchical assemblies of Co@CoO core-shell nanoplates exhibit excellent photocatalytic activity (the maximum value of O 2 yield is over 96%). Even after the sixth run, the high catalytic activity of the recovered Co@CoO core-shell nanoplates remained.
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
CARBON
·
2025
·
IF 11.6
Xianghong Li,Yuan Shu,Tingkai Zhao,Jalil abdul,Haoxin Duan,Muyang Ma,Tao Jiang,Yanzong Liu
Electromagnetic functional materials are playing an increasingly vital role in electromagnetic interference shielding, stealth protection, and information security. Carbon nanotubes (CNTs), owing to their unique structure and outstanding electromagnetic properties, have attracted widespread attention. Here, a 3D Co/CoO/RGO/CNT crosslinked heterostructure was fabricated by in-situ growth of CNTs on Co(CO 3 ) 0 · 5 (OH)·0.11H 2 O precursors that were crosslinked with reduced graphene oxide through a combined hydrothermal and chemical vapor deposition strategy. The resulting interconnected conductive heterostructures significantly enhanced electron transport, interfacial polarization, and impedance matching. Notably, the optimized composites achieved a minimum reflection loss of −23.95 dB with an effective absorption bandwidth of 4.2 GHz (at 10 wt% filler loading and 2.17 mm thickness), fully covering the X-band. Furthermore, the study of heterointerfaces between different components and their underlying loss mechanisms provides critical insights into the electromagnetic wave absorption behavior and guides the rational design of advanced structural materials. Density functional theory simulations were also employed to investigate the electronic structure and charge distribution at the Co–CoO and Co–CNT interfaces. The simulation results reveal that charge redistribution and the formation of interface dipoles contribute to enhanced dielectric and magnetic losses, offering a microscopic explanation for the superior microwave absorption performance.
研究领域:
材料科学
·
电磁功能材料
·
纳米复合材料
·
微波吸收
·
界面工程
✓ 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）