JOURNAL OF MOLECULAR STRUCTURE
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2021
·
IF 3.196
Jingyan Zhu,Baolin Liu,Weibing Zhang,Jun Jiang,Xinhua Li
Single-molecule magnets in cobalt clusters is much less well known than it is in manganese(II)/(III)/(IV) clusters. To explore new types of cobalt clusters and their potential applications, a new mixed valence coordination polymer ([Co(III) 3 Co(II) 2 (mba) 6 (Hdtba) (H 2 O) 4 ] n , H 2 dtba=2,2’-dithiodibenzoic acid, H 2 mba=2-mercaptobenzoic acid) ( 1 ) is constructed by employing cobalt chloride hexahydrate and H 2 mba as starting reactants under hydrothermal conditions. Single-crystal XRD studies indicate that 1 consists of a trinuclear cobalt(III)-sulfur cluster moiety and two discrete cobalt(II) nodes, which result in the formation of a covalent three-dimensional complex network. Similarly, the cobalt(III) cluster moiety acts as a building unit in this infinite coordination polymer 1 instead of the discrete and tiara-like clusters previously reported in the literature. Magnetic studies show its slow magnetic relaxation in the absence of an applied dc field, which is characteristic behavior of single-ion magnets, caused by the individual Co(II) ions.
研究领域:
无机化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Materials Horizons
·
2023
·Vol. 10
·期 12
·5633-5642
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IF 13.3
Yucheng Wu,Yanli Yu,Wei Shen,Yimin Jiang,Rongxing He,Ming Li
It is a promising pathway to use anions to regulate electronic structures, reasonably design and construct highly efficient catalysts for water splitting. Herein, a N-regulated Co cluster catalyst confined in carbon nanotubes, N-Co NCNTs, was constructed successfully. Nitrogen anions played a crucial role in optimizing the electronic structures of Co clusters and enhancing localization of electrons, resulting in polarized cobalt clusters. The N-induced electronic localization and the resulting polarized Co clusters are responsible for the improvement of catalytic activity. N-Co NCNTs exhibited ultra-low overpotentials of 178 mV and 92 mV for the OER and HER to achieve 10 mA cm−2 in an alkaline electrolyte, respectively. Its long-term catalytic durability is mainly attributed to the obstacle to the surface oxidation of Co clusters caused by N-regulation. N-Co NCNTs maintained a stable current density for 160 h at 10 mA cm−2. DFT computations confirmed the decisive role played by nitrogen anions in regulating the electronic structure. This work provides a pathway for understanding and designing highly efficient anion-regulated catalysts.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Jiajun Xu,Chao Bian,Jiayu Sun,Dong Liu,Xiaobin Wang,Zhiwei Xue,Xiuxia Meng,Hongjing Wu
The employment of electromagnetic (EM) absorbers integrating elaborate architecture, enhanced microwave absorption and multifunctional features remains a formidable challenge in practical applications including military stealth and incoming 5G electronic information era. Herein, a novel microwave absorber has been fabricated by in-situ growing carbon nanotubes (CNTs) on the prismatic nickel–cobalt (NiCo) clusters derived from Ni-Co layered double hydroxides (NiCo-LDH) via catalytic carbonization of ethyl acetate. The NiCo/CNTs composites with highly porous texture could provide sufficient open space to balance the impedance and introduce magnetic loss mechanism. Accordingly, the absorbers achieved remarkable EM absorption performance with a minimum reflection loss of –46.2 dB at 1.5 mm and broad bandwidth of 5.8 GHz owing to synergistic magnetic-dielectric effects and distinct structural merits. The NiCo/CNTs absorber manifests superior radar wave attenuation by the radar cross section simulation and density functional theory (DFT) was also performed to elucidate the potential mechanisms of the heterostructure formation and performance enhancement in the NiCo/CNTs composites. This work is expected to provide new insights or inspirations to modulate EM properties by rationally designing heterostructure for the elimination of severe EM pollution.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2019
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IF 2.938
Zhijie Wang,Anxiang Guan,Mayfair C. Kung,Anyang Peng,Harold H. Kung,Ximeng Lv,Gengfeng Zheng,Linping Qian
Aerobic oxidation of α-C H bond of organic compounds to valuable chemicals is widely investigated in both fundamental research and industry. Due to the good stability of molecular oxygen, severe reaction conditions are generally required. Herein, by in situ synthesis we used molecular oxygen to induce cobalt nanoclusters with the sensitive catalysis in mild selective oxidation. The cobalt containing clusters with an average diameter around 0.9 nm are in situ prepared in the presence of cis -cyclooctene epoxidation and cyclooctene dimer oxide is formed at the interface to stabilize Co clusters with electron donation as an oil-soluble surfactant. The soluble clusters exhibit high activity in selective oxidation of α-C H bond of ethylbenzene into acetophenone and turnover number (TON) reaches about 7 × 10 4 during 50 h’ reaction at 373 K, which is around 960 times more active than the one using CoCl 2 salt as the catalyst, resulting from efficient mass transportation, π bond interaction and oxygen gas activation. Extended work based on this understanding demonstrates that cobalt nanoclusters also effectively catalyze aerobic oxidation of cyclohexene.
研究领域:
化学催化
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有机合成
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
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2017
·Vol. 7
·期 7
·4102-4107
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IF 3.108
Jialing Li,Yi Jiang,Qian Zhang,Xiaochen Zhao,Na Li,Haili Tong,Xiaoxuan Yang,Lixin Xia
A simple and effective method to prepare photocatalytically active electrodes for water oxidation is described in this paper. The precious-metal-free catalyst, Co4O4(O2CMe)4(4-vinylpy)4 (py = pyridine) was electrochemically polymerised on a RuP-sensitised TiO2 (RuP = [Ru(bpy)2(4,4′-(PO3H2)2bpy2)]Cl2) and on a TiO2 surface codecorated with vinyl phosphate (Vpa) and RuP for applications in molecular photoelectrochemical (PEC) devices. With a Vpa chain as the anchoring group, the photoanode poly-Co4O4+Vpa/RuP/TiO2 demonstrated a significantly higher PEC performance compared to poly-Co4O4/RuP/TiO2. The introduction of a Vpa chain allows better immobilisation of catalyst and enhances the electron transport between the photosensitiser and the catalyst. A photocurrent density of ∼100 μA cm−2 was achieved in a Na2SO4 solution at pH 7.0 under a 0.4 V external bias, with a faradaic efficiency of 76% for oxygen production.
研究领域:
材料科学
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电化学
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催化化学
✓ 已验证
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
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2022
·
IF 5.876
Kaiwei Wang,Fumin Wang,Yi Zhai,Xu Zhang,Linfang Jiang,Zhibo Xu,Mengyue Li,Mengyao Li,Xubin Zhang,Mingshuai Sun
Zeolites with metal clusters encapsulated within the pore structure have attracted more attention because of their unique properties with high stability, but diffusion resistance is the bottleneck limiting the utilization efficiency of active centers, especially in macromolecular reactions. Hollow zeolites could effectively improve mass transport by reducing the wall thickness. In this work, cobalt-base hollow silicate-1 zeolite was obtained by mother liquid treatment with sodium chloride. Various characterization results show that the CoOx@HS-1-0.5Na + crystals have completely hollow structure and small cobalt cluster highly dispersed encapsulated in it. The presence of Lewis acid sites and the unique hollow structure resulted in enhanced selectivity to benzaldehyde in the styrene oxidation . The effect of various factors including cobalt loading, the concentration of sodium ion , reaction solvents and H 2 O 2 /styrene molar ratio on the catalytic performance were systematically investigated. The yield of benzaldehyde can achieve 73.8% with 83.59% styrene conversion and 88.29% benzaldehyde selectivity.
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2025
·
IF 9.7
Shuai Gao,Yuxi Song,Huan Yang,Ning Wang,Juan Yang
Rechargeable zinc-air batteries (ZABs) hold great promise for next-generation energy storage, but their practical application depends on the development of efficient bifunctional catalysts capable of catalyzing both the oxygen reduction reaction (ORR) during discharge and the oxygen evolution reaction (OER) during recharge. Herein, we propose a high-performance bifunctional oxygen electrocatalyst for ZABs, fabricated by encapsulating Co clusters into zeolite imidazole framework-8 (ZIF-8)-derived carbon via a supercritical CO 2 (scCO 2 ) fluid-assisted method. The dual-protection combining spatial confinement from porous carbon frameworks and strong Co-N coordination anchoring enables the stabilization of high-density Co clusters and preventing its aggregation. Furthermore, the scCO 2 treatment reconstructs the mesoporous structure, significantly improving mass transport and exposing more accessible active sites. Density functional theory (DFT) calculations demonstrate that the surface Co-N moieties serve as highly active centers for the ORR, whereas the metallic Co sites within the clusters predominantly drive the OER. As a result, Co@N–C exhibits a remarkably low potential gap (ΔE = 0.68 V) between ORR and OER. When applied in aqueous ZABs, the catalyst delivers an impressive specific capacity of 780 mAh g Zn −1 and a peak power density of 170 mW cm −2 , surpassing Pt/C + RuO 2 . Moreover, the solid-state ZABs assembled with this catalyst achieve a high peak power density of 87.0 mW cm −2 along with long-time cycling stability of 200 h, demonstrating great potential for flexible and portable energy storage devices.
研究领域:
材料科学
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电化学
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能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POWER SOURCES
·
2024
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IF 8.1
Miao Cheng,Wentao Xia,Ruirui Wang,Shaoqing Pan,Tongyu Shen,Qianqian Liu,Jing Hu,Tao Wei,Yun Ling,Wanfei Li,Bo Liu
Exploring multifunctional sulfur host materials with high immobilization ability and catalytic activity is of great significance for realizing high-performance Lithium-sulfur (Li–S) batteries. Recently, cellulose nanocrystals (CNCs) receive extensive attention for advanced energy storage applications owing to their intrinsically exceptional physical/chemical properties and natural abundance. Herein, a highly dispersed cobalt clusters/nanoparticles embedded into CNC derived carbon aerogel composite (CA/Co-2) is for the first time synthesized. Benefiting from the interconnected hierarchical porous structure, homogeneously anchored Co clusters/nanoparticles and N-doped species, the designed CA/Co-2 could enable rapid electron/ion transport, efficient sulfur utilization, effective suppression of the shuttle effect and fast catalytic conversion of polysulfides , thereby contributing to outstanding electrochemical performance. Consequently, CA/Co-2@S cathode delivers high initial discharge capacity (1553.1 mAh g −1 at 0.1C) and superior cycle stability. Moreover, a remarkable rate performance of 681.4 mAh g −1 at 5.0C and exceptional long-term cycling stability with an ultralow capacity decay of 0.028 % per cycle at 5.0C over 1000 cycles could be achieved when coupled with carbon paper interlayer. This work develops a workable strategy for fabricating multifunctional sulfur host derived from the fascinating bio-nanomaterial of CNC, which provides valuable guidance for the future design of high-performance Li–S batteries.
研究领域:
材料科学
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能源存储
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 9
·期 17
·10893-10908
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IF 12.732
Yuanyuan Zhang,Yunfeng Qiu,Zhuo Ma,Yanping Wang,Yongxia Zhang,Yuxin Ying,Yinan Jiang,Yixue Zhu,Shaoqin Liu
The simultaneous improvement of intrinsic activities and the number of active sites in electrocatalysts is the bottle-neck issue for H2 production. Herein, commercial CNTs serving as conductive kernels are in situ coupled with 3D ZIF-67 derived Co/CoP core-corona clusters. Such a hierarchical bead string nanostructure not only possesses highly exposed active sites, but also favours fast electron transfer for electrocatalytic kinetics. Our material shows excellent HER (η10 = −151 mV) and glucose oxidation reaction (GOR) performance, showing a smaller hybrid water splitting potential of 1.42 V compared to conventional water splitting (η10 = 1.74 V) for H2 production. DFT calculations indicate that the Schottky heterointerface at Co/CoP decreases the initial H2O dissociation energy barrier and possesses a thermoneutral H* adsorption free energy for the HER, as well as reducing the energy barrier for the GOR. Meanwhile, more oxidative cobalt oxyhydroxide favoured the GOR process. The present work opens a new avenue for designing Mott–Schottky multifunctional electrocatalysts for both energy-saving H2 production and value-added products.
研究领域:
材料科学
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能源化学
·
催化科学
✓ 已验证
DOI
高影响因子
CARBON
·
2020
·
IF 8.821
Xingwei Zhou,Xin Liu,Jiahao Zhang,Cai Zhang,Seung Jo Yoo,Jin-Gyu Kim,Xianyu Chu,Chao Song,Peng Wang,Zhenzhen Zhao,Dabing Li,Wei Zhang,Weitao Zheng
Preventing agglomeration and corrosion of metal electrocatalysts at nanoscale is crucial for electrochemical energy conversion, such as fuel cell and overall water splitting , where all the oxygen evolution reaction (OER), hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) are the core. Herein, an effective strategy is developed for preparing multifunctional self-supporting electrocatalysts with uniformly distributed cobalt nanoparticles and clusters. Benefiting from good electrical conductivity and multiple active sites, the trifunctional self-supporting catalyst free from stacking and aggregating exhibits excellent OER and HER activities with an overpotential of 270 and 110 mV to obtain a current density of 10 mA cm −2 in alkaline media . The ORR performance was tested in 0.1 M KOH solution with a half-wave potential of ∼0.80 V and a limiting current density of ∼ −4.8 mA cm −2 . Our finding provides an opportunity for the rational design of multifunctional and highly-efficient self-supporting electrocatalysts towards the integration of electrochemical energy conversion.
研究领域:
材料科学
·
电化学能源转换
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2023
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IF 22.1
Huiling Zhang,Xiaomei Zhou,Longxin Liu,Fujun Lan,Teng Zhao,Mo Qiu,Qingxin Guan,Wei Li
Atomically dispersed cluster catalysts own versatile applications in biomass valorization, while the controllable assembly and microenvironmental regulation remain a crucial challenge. Herein, Co clusters assembled via nanosized ZIF-67 sprouted from Co-Al layered double hydroxide nanoflowers were applied for selective hydrogenation of furfural (FAL). The pyrolysis temperature can tune the microstructures and acid properties of the catalyst, which accounts for the hydrogenation of FAL to furfuryl alcohol (FOL), 2-methylfuran (2-MF), and tetrahydrofurfuryl alcohol (THFOL) with yield of 99.1 %, 96.7 %, and 82.3 %, respectively. The Co clusters favor C O bond adsorption via bridging-type adsorption mode while suppressing the furan ring adsorption. Moreover, ultra-dispersed Co clusters facilitate the cleavage of C-OH bonds in FOL intermediate, leading to a high 2-MF yield. As the pyrolysis temperature increase, the formed Co nanoparticles are conducive to the parallel adsorption of FAL, resulting in the production of THFOL. This work affords a multi-functional catalyst in catalytic biomass upgrading.
研究领域:
催化
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材料科学
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化学工程
·
生物质转化
✓ 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）