CHINESE CHEMICAL LETTERS
·
2023
·
IF 9.1
Zhenqiang Guo,Huicong Yang,Qian Wei,Shengjun Xu,Guangjian Hu,Shuo Bai,Feng Li
ABSTRACT Sulfurized polyacrylonitrile (SPAN) is proposed as a promising cathode material for lithium sulfur batteries. However, the continuous side reactions at the electrolyte-electrode interfaces as well as the slow redox kinetics of SPAN cathode deteriorate the electrochemical performance. In this study, an electrolyte with dual-additives comprising 2-fluoropyridine (2-FP) and lithium difluorobis (oxalato) phosphate (LiDFBOP) was used to improve the performance of Li||SPAN cells. 2-FP has a lower lowest occupied molecular orbital energy than that of the solvents in the electrolyte, leading to its prior reduction. A LiF-rich film can be formed on the electrode, effectively improving the stability of the electrolyte-electrode interfaces and prolonging the life. Simultaneously, LiDFBOP could form an electrolyte-electrode interface film containing a large amount of Li x PO y F z species, compensating for the kinetic deterioration caused by the lower ionic conductive of LiF formed at the electrolyte-electrode interface. Hence, an electrode-interface film with good chemical stability and high Li + transport was established by LiF and Li x PO y F z -rich species. The Li||SPAN cell with the electrolyte containing dual-additives demonstrates an excellent capacity retention of 97.5% after 200 cycles at 1.0 C, 25 °C, comparing to 56.2% capacity retention without additives. Moreover, the rate capacities of cells with dual-additives can reach 1128.1 mAh/g at 5 C, comparing to only 813.5 mAh/g using electrolyte without additives. Our results shown that the dual-additives in electrolyte provide a promising strategy for practical application of lithium sulfur batteries with SPAN cathodes.
研究领域:
材料科学
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电化学
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能源存储
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产品关联
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2025
·Vol. 39
·期 7
·e70253
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IF 0
Chiyuan Wang,Xin Long,Changwei Shao,Jiawei Huang,Jiaqi Ren
Preparing polysilazoxanes with a controlled molecular structure is the ideal route for fabricating Si O C N ceramics with adjustable composition and properties. In this paper, liquid polysilazoxanes were synthesized via a controlled substitution reaction between trichlorosilane and alcohols (R OH), followed by the condensation with ammonia. By adjusting the alkyl groups (R tert -butyl, dioxane and triazolylmethyl) of alcohols, three kinds of polysilazoxanes with Si N Si backbones, but different side chains were synthesized. During high-temperature pyrolysis, tert -butoxy groups in polysilazoxanes are easily removed, producing low-carbon (< 4 wt%) ceramics, while dioxane and triazolylmethyl groups decompose to form oxygen-rich and nitrogen-rich ceramics, respectively. Due to the composition distinction, the resulting Si O C N ceramics showed quite different high-temperature behavior. This report provides a direct and effective method for obtaining polysilazoxanes with a controlled molecular structure, which is useful for fabricating Si O C N ceramics with improved high-temperature performance.
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DOI
Soft Matter
·
2021
·Vol. 17
·期 30
·7158-7167
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IF 3.679
Hanqi Xu,Jinbo Wu,Yaying Hong,Weijia Wen
The impact of two nonionic surfactants, namely Span 20 and Span 85, on the electrorheological response and colloidal stability of urea-coated barium titanyl oxalate (BTRU)/silicone oil suspensions is investigated. We quantitatively analyze the surfactant effect on modified ER performance through the measurements of yield stress and current density, as well as the tuned suspension stability through calculation of the Turbiscan stability index (TSI) and naked-eye observations of sedimentation phenomena. The surfactant effect on particle–oil interactions and agglomeration effects is examined by measuring the permeability of silicone oil when mixed with the Span surfactant and the cluster size of particles in dispersing medium, respectively. Our results indicate that with the presence of a Span surfactant, the yield stress of the suspension exhibits a local maximum at certain Span concentrations. We hypothesize that below the optimal Span concentration, the ER properties are enhanced by the increase of the electrostatic interaction between particles. Above the limiting concentration, the ER activity is weakened by the formation of a double-layer surfactant structure that generates a steric hindrance effect. We discover that the addition of the Span surfactant favors the improvement of the particle agglomeration phenomenon, thereby promoting colloidal stability of the suspension. Consequently, in the consideration of both ER properties and suspension stability, an optimal ER fluid with the addition of 0.4 wt% Span 85 is acquired with remarkable integrated ER properties.
研究领域:
材料科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
ChemSusChem
·
2015
·Vol. 8
·期 12
·2066-2072
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IF 7.657
Yehong Wang,Jian Zhang,Jing Liu,Chaofeng Zhang,Zhixin Zhang,Jie Xu,Shutao Xu,Fangjun Wang,Feng Wang
Graphical CO 2 -mediated reactions: CO 2 -mediated metathesis reactions between amines and DMF to synthesize formamides are described. The N -formylation of amines to formamides is achieved by activating amines, not DMF, via a C N and N H bond metathesis reaction. Using this method, primary, secondary, aromatic, and heterocyclic amines as well as diamines can be obtained with good to excellent formamide yields. Herein, we report CO 2 -mediated metathesis reactions between amines and DMF to synthesize formamides. More than 20 amines, including primary, secondary, aromatic, and heterocyclic amines, diamines, and amino acids, are converted to the corresponding formamides with good-to-excellent conversions and selectivities under mild conditions. This strategy employs CO 2 as a mediator to activate the amine under metal-free conditions. The experimental data and in situ NMR and attenuated total reflectance IR spectroscopy measurements support the formation of the N -carbamic acid as an intermediate through the weak acid–base interaction between CO 2 and the amine. The metathesis reaction is driven by the formation of a stable carbamate, and a reaction mechanism is proposed.
研究领域:
有机化学
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绿色化学
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DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
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2021
·Vol. 32
·期 5
·2106886
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IF 18.808
Haisheng Gong,Zengxi Wei,Zhichao Gong,Jingjing Liu,Gonglan Ye,Minmin Yan,Juncai Dong,Christopher Allen,Jianbin Liu,Kang Huang,Rui Liu,Guanchao He,Shuangliang Zhao,Huilong Fei
Electrochemical H 2 O 2 production through the 2-electron oxygen reduction reaction (ORR) is a promising alternative to the energy-intensive anthraquinone process. Herein, by simultaneously regulating the coordination number of the atomically dispersed cobalt sites and the nearby oxygen functional groups via a one-step microwave thermal shock, a highly selective and active Co N C electrocatalyst for H 2 O 2 electrosynthesis that exhibits a high H 2 O 2 selectivity (91.3%), outstanding mass activity (44.4 A g −1 at 0.65 V), and large kinetic current density (11.3 mA cm −2 at 0.65 V) in 0.1 m KOH is obtained. In strong contrast to the typical Co N 4 moieties for the 4-electron ORR, the present Co N C catalyst possesses a low-coordinated Co N 2 configuration and abundant epoxide groups, which work in synergy for promoting the 2-electron ORR, as demonstrated by a series of control experiments and theoretical simulations. This study may provide an effective avenue to modulating the composition and structure of electrocatalysts at the atomic scale, leading to the development of new electrocatalysts with unprecedented reactivity.
研究领域:
材料科学
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电化学
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催化科学
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产品关联
DOI
高影响因子
AICHE JOURNAL
·
2023
·Vol. 69
·期 9
·e18149
·
IF 3.7
Yongxiao Tuo,Ying Meng,Qing Lu,Qing Wang,Furong Jia,Yan Zhou,Xiang Feng,Jun Zhang,Xuezhi Duan,De Chen
The enhancement of catalytic activity is always limited by the dilemma in activation and desorption due to Sabatier principle. Locating the Sabatier optimum by manipulating catalyst electronic structure has been a long-standing challenge in heterogeneous catalysis. Herein, we presented a generic strategy to continuously tailor the Pt 5d state occupancy via tuning the Pt O Mn electronic linkage over Al 2 O 3 -confined MnO x islands, aiming at accommodating the C H cleavage and product desorption capabilities in dehydrogenation of liquid organic hydrogen carriers (monocyclic/bicyclic hydrides). Rising Mn valence can decrease the Pt 5d state occupancy through more electron transfer from Pt 5d to O 2p due to the strong π-donation of O 2p to Mn 3d. This will lead to the lower initial C H activation energy barrier while higher product desorption energy barrier. An intermediate Pt 5d filling of ~8.4 in Pt Mn 2 O 3 /Al 2 O 3 enables the balanced level of product desorption and C H activation, thus ensuring a superior dehydrogenation activity. The electron structure-adsorption-performance modulation mechanism described herein provides a benchmark to locate the Sabatier optimum for the metal catalyst design.
研究领域:
多相催化
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材料科学
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化学工程
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物理化学
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DOI
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
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2022
·Vol. 97
·期 10
·2805-2814
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IF 3.709
Shuaibin Zhang,Bochao Yan,Zhihui Chen,Suping Zhang
BACKGROUND Levulinic acid, an important platform compound, is extensively used in textiles, dyes, antifreeze, animal feed, solvents and food additives. However, the use of lignocellulosic biomass to produce levulinic acid is difficult because of poor accessibility to cellulose and low hydrolytic yield. Thus a viable hydrolysis strategy and a suitable catalyst must be developed. RESULTS In this study, a bifunctional solid acid catalyst (HTC-SO 3 H) containing both cellulose binding sites ( Cl, COOH and OH) and catalytic sites ( SO 3 H) was prepared by a carbonization–grafting–oxidization method. X-ray photoelectron spectroscopy and Fourier transform infrared characterization confirmed the existence of Cl and the successful modification of the SO 3 H grafted hydrothermal carbon. The hydrogen bonds formed between cellulose and the binding sites ( Cl, OH and COOH) in the catalyst showed synergistic effects with the catalytic sites ( SO 3 H), leading to efficient hydrolysis of the furfural residue. A total of 74.81% (non-magnetic) and 70.18% (magnetic) levulinic acid yields were obtained after hydrolysis at 190 °C and 180 min in γ-valerolactone–H 2 O (1:1, v/v). Magnetic catalysts were synthesized using a co-precipitation method. Catalysts were recycled without any obvious reduction in catalytic activity. CONCLUSION Using sucralose as a raw material, the as-synthesized bifunctional solid acid catalyst improved the accessibility to cellulose and increased levulinic acid yield. Moreover, the grafted SO 3 H formed by hydroxyl hydration condensation exhibited superior stability. This study provides a valuable strategy for the efficient hydrolysis of lignocellulosic biomass. © 2022 Society of Chemical Industry (SCI).
研究领域:
生物化学
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催化化学
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可再生能源
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产品关联
DOI
高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2014
·Vol. 55
·期 3
·614-623
·
IF 1.441
Hao Li,Xian-Ming Zhang,Shi-Yang Zhu,Wen-Xing Chen,Lian-Fang Feng
Isocyanate- and amine-functionalized polypropylene (PP) and polystyrene (PS) were prepared through grafting and copolymerization method. These compounds are used as precursors for PP-graft-PS (PP-g-PS) copolymers and reacted at the matrix interface of PP/PS blends. Functionalized polymer structures were characterized by 1 H NMR and FTIR spectroscopy. The effects of the synthesized compatibilizer on the rheological and morphological behavior of PP/PS blends were investigated systematically. Results showed that the functional polymer was successfully synthesized, and the additional two different compatibilizer systems dramatically decreased the size of the dispersed phase domains in PP/PS blends. Compared with the uncompatibilized blends, compatibilized blends exhibited a slightly higher crystallization temperature because the melting points of the blend components were not evidently affected by the addition of compatibilizer, as revealed by differential scanning calorimetry. The compatibilizer effect on the PP/PS blends was reflected through rheological property and dynamic mechanical analysis. POLYM. ENG. SCI., 55:614–623, 2015. © 2014 Society of Plastics Engineers
研究领域:
高分子科学
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材料工程
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聚合物共混与复合材料
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聚合物改性
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DOI
高影响因子
AICHE JOURNAL
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2025
·
IF 4
Jinlin Mei,Zhentao Liu,Zhengkai Cao,Aocheng Wang,Xiaoyang Kong,Aijun Duan,Chunya Wang,Chunming Xu,Xilong Wang
Hierarchical Y/SBA-15 meso-microporous composites (YS- x ) and corresponding highly dispersed catalysts (Ni/YS- x ) were prepared and applied to the production of jet fuel range hydrocarbons by the selective hydrogenation of oleic acid. Small particle size and electron-deficient Ni δ+ are detrimental to the C C bond activation of the η 1 (C)-acyl conformation and inhibit the decarbonylation/decarboxylation pathway. Besides, the activation ability of the C C bond is regulated to avoid excessive cleavage by the acidity and diffusion properties of the hierarchical Ni/YS- x catalysts, thus affecting their hydroisomerization and hydrocracking properties. The abundant acid sites are beneficial to the selective activation of the C O bond of the η 2 (C, O)-aldehyde conformation and the promotion of the reductive deoxygenation pathway. The optimal Ni/YS-1 shows the highest iso / n -alkane ratio ( i / n = 6.26) and superior jet fuel range hydrocarbons yield (48.8%, 340°C), which is a benefit from its outstanding acid–metal balance and worthy diffusion property.
研究领域:
催化
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多孔材料
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化学反应工程
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能量转换
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表面化学
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产品关联
DOI
高影响因子
EcoMat
·
2024
·
IF 10.7
Junming Shi,Guoyang Gao,Can Jin,Hongqing Wu,Weizhen Wang,Yulong An,Zhen Zhou,Zhanhua Huang,Wenshuai Chen
Value-added conversion of lignocellulose is a sustainable approach. Photo-refining biomass is in line with current environmental protection strategies. However, photo-reforming biomass suffers from poor catalyst stability and low conversion efficiency. Here, we designed fructose as a lignocellulosic model. The heterogeneous structure of Prussian blue coating was constructed with a special covalent bond structure of Co CN Zn. This structure has a catalytic conversion mechanism that can accelerate electron transfer. Fructose was simultaneously converted to value-added platform compounds (5-HMF and formic acid) and gaseous fuels (CO, CH 4 ) with a conversion rate of up to 92.5%, which is more than 1.7 times than that of catalysts without adding Prussian blue. Hydrogen transfer and carbon transfer on the carbon atoms of fructose facilitates the production and accelerates the spillover of CO from formic acid. This work provides new ideas for the development of Prussian blue catalysts and the conversion of pentose.
研究领域:
化学工程
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催化科学
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环境科学
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产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2023
·
IF 19
Xian Tong,Yue Han,Li Zhu,Runqi Zhou,Zhiqiang Lin,Hongning Wang,Shengbin Huang,Yuncang Li,Jianfeng Ma,Cuie Wen,Jixing Lin
Zinc (Zn) and its alloys have recently gained research interest due to their good biosafety, biological function, biodegradability, and formability. Zinc-phosphate (ZnP) coating has been shown to improve the corrosion resistance and biocompatibility of Zn alloys. Here, a biodegradable ZnP-coating on Zn 1Cu 0.1Ti (ZCT) membrane with high strength-ductility and mechanical stability, suitable degradation rate, effective antibacterial ability, excellent in vitro and in vivo cytocompatibility, and osteogenesis is reported. The ZnP-coated ZCT exhibits high strength-ductility with a yield strength of 264 MPa, ultimate tensile strength of 312 MPa, elongation of 36.0%, and high mechanical stability before and after 30 d immersion in Hanks’ and AS solutions, all of which are higher than those of ZCT. The ZnP coating shows good deformation resistance, healing effect, and bond strength with the substrate, meeting the clinical contour shaping requirements. The ZnP-coated ZCT membrane sample shows higher cell viability toward MC3T3-E1 and MG-63 cells, osteogenic and mitochondrial quality-control properties in vitro than those of the ZCT sample. Using a rat calvarial defect model, the ZnP-coated ZCT membrane shows complete biosafety and considerable osteogenesis performance. Overall, the ZnP-coated ZCT membrane is recommended as a promising biodegradable implant material for oral guided bone regeneration application.
研究领域:
材料科学
·
生物材料
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生物医学工程
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牙科材料
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DOI
高影响因子
Small
·
2022
·Vol. 18
·期 40
·2202939
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IF 15.153
Hongli Yang,Dongdong Zhang,Yong Luo,Wenxiang Yang,Xiaoqiang Zhan,Weiyou Yang,Huilin Hou
Photocatalytic CO 2 reduction by solar energy into carbonaceous feedstock chemicals is recognized as one of the effective ways to mitigate both the energy crisis and greenhouse effect, which fundamentally relies on the development of advanced photocatalysts. Here, the exploration of porous microrod photocatalysts based on novel Ni Co O solid solutions derived from bimetallic metal–organic frameworks (MOFs) is reported. They exhibit overall enhanced photocatalytic performance with both high activity and remarkable selectivity for reducing CO 2 into CO under visible-light irradiation, which are superior to most related photocatalysts reported. Accordingly, the Ni 0.2 -Co 0.8 -O microrod (MR-N 0.2 C 0.8 O) photocatalyst delivers high efficiency for photocatalytic CO 2 reduction into CO at a rate up to ≈277 µmol g –1 h –1 , which is ≈35 times to that of its NiO counterpart. Furthermore, they display a high selectivity of ≈85.12%, which is not only better than that of synthesized Co 3 O 4 (61.25%) but also superior to that of reported Co 3 O 4 -based photocatalysts. It is confirmed that the Co and Ni species are responsible for CO 2 CO conversion activity and selectivity, respectively. In addition, it is verified, by adjusting the Ni contents, that the band structure of Ni Co O microrods can be tailored with favorable reduction band potentials, which thus enhance the selectivity toward CO 2 photoreduction.
研究领域:
材料科学
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环境科学
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化学
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能源科学
·
催化
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）