Molecular Catalysis
·
2023
·
IF 4.6
Wenyan Jia,Maoshuai Li,Mingchan Chen,Jing Lv,Mei-Yan Wang,Xiaojun Bao,Xinbin Ma
The epoxide methoxycarbonylation is essential for the synthesis of advanced aldehydes and polyols, but the reaction mechanism has not been well resolved yet. In this work, we have established more detailed mechanism pathways for ethylene oxide methoxycarbonylation over Co-based complexes, the reaction pathway of the main by-product acetaldehyde, and examined the effect of nitrogen-containing heterocycles on the pathways using DFT calculation and experimental study. The conversion of ethylene oxide and product selectivity is sensitive to the structure of nitrogen-containing heterocycles. The addition of pyrazole as a ligand generated the highest conversion (98.3%) and dramatically inhibited by-product (e.g., acetaldehyde, 2-methoxyethanol) formation with the highest selectivity of methyl 3-hydroxypropionate (84.3%). The calculations reveal that the epoxide ring opening is the rate-determining step and the homonuclear ion pair mechanism is the most energetically preferred pathway. The ligand with promoting effect on the methyl 3-hydroxypropionate formation rate can lower the energy barrier of the ring-opening step with a proportional correlation established.
研究领域:
化学工程
·
催化化学
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产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2023
·
IF 6.6
Jieqing Shen,Shuohan Liu,Dongyu Bian,Zhixin Chen,Hui Pan,Cheng Yang,Wensheng Tian,Yao Li,Lingti Kong,Hengdao Quan,Da-Wei Wang,Shenmin Zhu
Polyethylene oxide (PEO) based polymer electrolytes is promising for all-solid-state lithium metal batteries (ASSLMBs). Solid-electrolyte-interface (SEI) layer formed between polymer electrolytes and lithium metal is crucial to inhibit lithium dendrites growth. Herein, mild fluorination on commercial PEO is engineered as an electrolyte for ASSLMBs, which shows an outstanding cycling stability. During this process, some C-H bonds in PEO chains are substituted with C-F bonds, resulting in the formation of fluorinated PEO (F-PEO) with a low fluorine content of 2.7 at.%. Fluorination alters the regularity of PEO chains, leading to an improved ion conductivity for F-PEO/LiTFSI. An unusual and stable SEI containing relatively high LiF content forms, which can inhibit lithium dendrites growth and boost the battery performance. Li/Li cell with F-PEO/LiTFSI delivers outstanding cycling stability over 2000 h at 0.1 mA cm -2 . When matching with LiFePO 4 cathode, the battery exhibits high capacity of 151.0 mAh g −1 and good cycling stability for 500 cycles (0.05% decay per cycle) at 0.5 C. Even at 1.0 C, the capacity of the battery keeps at 99.8 mAh g −1 after 900 cycles. This facile and low-cost strategy opens an avenue for ASSLMBs towards their commercial applications.
研究领域:
材料科学
·
电化学
·
能源存储
·
高分子化学
·
纳米科技
·
固体离子学
·
电池技术
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2021
·Vol. 28
·期 12
·1-13
·
IF 3.097
Sun Chenkai,Yin Hai,He Junwei,Zou Liming,Xu Yongjing
Abstract On basis of the difficulty in fabricating natural-polymer nanofibers by electrospinning with common solvents, in this paper, gelatin/chitosan (CS)-Poly (ethylene oxide) (PEO) electrospun membranes at different weight ratios (9/1, 8/2, 7/3, 6/4) were successfully fabricated with 50% (v/v) acetic acid solution as solvent. Moreover, the relationship between different fiber components and the properties of as-spun membranes has been studied. All electrospun membranes were characterized by scanning electron microscopy, Fourier transform infrared, X-ray diffraction, thermogravimetric analysis, differential scanning calorimetry, porosity, contact angle, water swelling rate, water vapor transmission rate, mechanical properties, and in vitro degradation behavior. The results demonstrated that all electrospun membranes were consisted of uniform, bead-free fibers, and the average fiber diameter and porosity were 390-600 nm and 80-90%, respectively. The crystallinity of gelatin/CS-PEO electrospun membranes gradually increased with the increasing content of PEO. Besides, the water contact angle, water swelling ratio, water vapor transmission rate, and in vitro degradation behavior of gelatin/CS-PEO electrospun membranes were 29°-37°, 260-410%, 580-657 g·m −2 ·day −1 , and 79-91%, respectively. Moreover, the mechanical properties showed that the tensile strength, Young’s modulus, and elongation at break were 0.76-1.70 MPa, 21.0-31.7 MPa, and 22.3-27.4%, respectively. In particular, gelatin/CS-PEO electrospun membranes 7/3 have excellent properties comparing with others, showing the great potential application as dermis scaffold in skin regeneration.
研究领域:
生物材料
·
组织工程
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2023
·
IF 5.3
Habib Ullah,Zakir Ullah,Zafar A. K. Khattak,Mohsin Ali Marwat,Baoyi Yu,Hyung Wook Kwon,Hyun You Kim,Francis Verpoort
Transforming atmospheric CO2 into industrially valuable cyclic carbonates is of great importance and one of the attractive approaches for reducing CO2 concentration in the biosphere. However, the selectivity and conversion of ruthenium catalysts for cyclic carbonate formation via CO2 insertion to epoxides are low at high pressure. Here, a series of novel ruthenium complexes supported by ONN pincer-type hydrazone ligands were successfully generated, and their potential for CO2 valorization to cyclic carbonates was investigated. NMR, Fourier transform infrared (FT-IR), mass spectrometry, elemental analysis, and single-crystal diffraction analysis further confirmed the structures of these ruthenium compounds. These compounds were utilized for the CO2/coupling reaction after thorough characterization. Fortunately, these complexes outperform the reported ruthenium catalysts with a turn-over frequency of 833 h–1 and >99% selectivity at atmospheric pressure without any assisted cocatalyst. The designed catalyst showed consistent catalytic performance over five repeating cycles.
研究领域:
化学
·
环境科学
·
催化反应
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Zhiang Li,Shuai Liu,Hao Xu,Fan Ding,Weimin Wang,Kaikai Song,Ting Liu,Lina Hu
Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (LLZTO) is widely used in polyethylene oxide (PEO) based solid electrolytes preparation due to its high ionic conductivity, electrochemical stability towards lithium and excellent mechanical properties. However, agglomeration of LLZTO and the inert interfacial layer for Li + transport between LLZTO and PEO limit its application. Herein, we systematically study the effect of different contents of 1-methyl-1-propylpiperidinium bis(trifluoromethylsulfonyl)imide (denoted as PP13-TFSI) ionic liquid on PEO/LLZTO composite solid electrolytes (CSEs). PP13-TFSI, which provides a new pathway for Li + transport and promotes the uniform dispersion of LLZTO. By adjusting the proportion of PP13-TFSI reasonably, the agglomeration of LLZTO is weakened, the crystallinity of PEO is reduced, and the growth of lithium dendrites is also inhibited. Therefore, the CSEs with high ionic conductivity (2.03 × 10 −4 S cm −1 , 30 ℃) enhanced by PP13-TFSI. Li||Li symmetric batteries exhibit stable cycling up to 6000 h at 60 °C, and can cycle stably for up to 3000 h at 28 °C. LiFePO 4 ||Li full batteries exhibit high-capacity retention rate (≈ 90.5 %) after 500 cycles at 1 C. This work not only systematically study the effects of different contents of PP13-TFSI on CSEs, but also provide a simple composite solid electrolyte strategy.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Foods
·
2022
·Vol. 11
·期 24
·4073
·
IF 5.561
Yingrui Ji,Dongming Lan,Weifei Wang,Kok Ming Goh,Chin Ping Tan,Yonghua Wang
With the prevalence of edible diacylglycerol (DAG) oil, which is beneficial to human, the generation of 3-monochloropropanediol esters (3-MCPDE) and glycidyl esters (GE) as well as the stability of physical properties during heat-induced processing still need to be explored. In this study, the experiment used olive-based edible oil with different contents of DAG (40, 60, and 80%) to make crackers and fry chicken. They were heated at 160 and 180 °C to determine the changes in 3-MCPDE and GE, the crackers’ hardness and gumminess, and the physical properties of the oil. During baking and frying, 3-MCPDE decreased, while the content of GE slightly increased with the prolonged heating duration. Finally, 3-MCPDE and GE were lower than 1.25 mg/kg and 1.00 mg/kg, respectively. The AV increased proportionally as duration increased and POV was below 0.30 g/100 g. In general, the changes in 3-MCPDE and GE were related to the heating temperature and duration, and not significantly (p> 0.05) related to the content of DAG.Keywords:3-MCPD ester;glycidyl ester;diacylglycerol;crackers;frying oil
研究领域:
食品科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Ruolin Cheng,Anhu Wang,Shuxun Sang,Huagen Liang,Shiqi Liu,Panagiotis Tsiakaras
The CO 2 cycloaddition of epoxides is a highly attractive long-term carbon fixation strategy, but harsh reaction conditions and expensive catalytic materials limit its industrial application. Herein, low-cost and highly efficient W 18 O 49 -based composites were constructed by in-situ solvothermal synthesis. It is found that W 18 O 49 /g-C 3 N 4 composites exhibit the highest yield of 74% (271 mmol g −1 h −1 ) in the probing reaction of styrene carbonate production. The physicochemical characterizations indicate that the photocatalysis plays a fundamental role in this reaction by promoting the activation of CO 2 and styrene oxide. The crucial role of photogenerated electrons and Lewis acid-base sites is confirmed. In this work, a novel catalyst selection to produce cyclic carbonate under ambient conditions is presented.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2012
·Vol. 26
·期 11
·600-603
·
IF 2.061
Dongsheng Bai,Huanwang Jing,Guangjian Wang
The synthesis of cyclic carbonates from epoxides and carbon dioxide catalyzed by cyanocobalamin and n -Bu 4 NI system was achieved under 0.8 MPa CO 2 pressure at 140°C without organic solvents. Propylene carbonate was obtained in 99% yield within 6 h under the optimized reaction conditions. The cyanocobalamin catalyst could be recycled with water and retained moderate catalytic activity. Copyright © 2012 John Wiley & Sons, Ltd.
研究领域:
化学
·
环境科学
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产品关联
DOI
高影响因子
CHEMISTRY OF NATURAL COMPOUNDS
·
2019
·Vol. 55
·期 1
·172-174
·
IF 0.567
Zhang H.,Wu J.,Zhu F.,Zhang X.,Zhu X.
P. N. Reddy, S. Mohanty, and S. K. Nayak, Technol. Eng.,
53, 1723 (2014).
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V. P. Kommula, K. Obi Reddy, S. Mukul, M. Tshilidzi, and V. A. Rajulu, Int. J. Polym. Anal.,
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研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Yongjian Wei,Ying Li,Yunfei Xu,Yuze Zu,Yinghui Sun,Tong Xu,Haiou Liang,Jie Bai
Exploring the impact of metal oxide crystal facets on the cycloaddition reaction of CO 2 with epoxides is meaningful because pure metal oxides exposing specific crystal facets show considerable promise as catalysts for industrial applications. In this study, we developed a simple strategy to prepare single-crystal ZnO nanosheet materials with controllable crystal facets through hydrothermal synthesis, followed by pyrolysis under different atmospheres. Studies revealed that the formation of ZnO single-crystal nanosheets involves the decomposition of the precursors and an ordered phase transition. Based on the quantitative correlation between oxygen vacancies, surface Zn, and the catalytic activity of ZnO (002) with varying numbers of oxygen vacancies, together with TPD, Py-IR, in-situ EPR, fluorescence spectroscopy characterizations, and DFT calculations, a synergistic mechanism between oxygen vacancies and surface Zn was proposed. Specifically, oxygen vacancies are the active sites for CO 2 , whereas saturated coordination surface Zn atoms activate epoxides. At 125 °C, 2 MPa, and 4 h, 93.3 % yield of the product was achieved using only 5 mg of the optimal ZnO catalyst. The excellent performance, stability, and applicability of single-crystal nanosheets make them ideal candidates for industrial applications. This study provides a new insight into the catalytic mechanisms of CO 2 cycloaddition over metal oxides.
研究领域:
材料科学
·
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Jinlai Shen,Zhiwen Lei,Chaoyang Wang
Solid polymer electrolyte with broad electrochemical stability window is regarded as the most promising candidate for high-voltage lithium metal batteries enabling high specific energy density. However, solid polymer electrolyte without particular protection is not facile to realize stable cycle of LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) cathode at high voltage because of the strong oxidizing property from the direct contact between cathode and electrolyte. Herein, an ion conducting asymmetric poly(ethylene oxide) (PEO) based electrolyte composed of zeolitic imidazolate framework (ZIF-8)@ionic liquid protective coating on NCM811 cathode surface and PEO-based electrolyte with ZIF-8 nanofillers on lithium metal anode is prepared in order to construct high-performance solid-state lithium metal batteries. The as-prepared asymmetric composite electrolyte exhibits a high ionic conductivity of 9.02 × 10 -4 S/cm at 60 °C and broad electrochemical stability window of above 4.9 V. Notably, the as-prepared cells exhibit the highest discharge capacity of 150 mAh/g at 0.2C under 60 °C. It is found that the ZIF-8@ionic liquid protective coating effectively prevents the oxidative decomposition of PEO based electrolyte at high voltage and the transition metal dissolution from the cathode. Meanwhile, the growth and penetration of lithium dendrites are also restrained, which shows significant potential for boosting the commercialization of high-voltage lithium metal batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Zengkun Li,Rui Xu,Wenfei Shen,Yao Wang,Zhongjie Cheng,Yulin Niu,Jun Li,Matt J. Kipper,Laurence A. Belfiore,Jianguo Tang
Dynamic control of fluorescence to meet the evolving demands of optoelectronic devices is garnering significant attention. Current strategies primarily focus on altering the chemical environment of the luminescent centers using external substances, such as quenchers, without considering modifications to the fluorescent groups themselves for luminescence control. In this work, we investigate a novel electro-quenching device that incorporates europium (Eu 3+ ) complexes into a polyethylene oxide (PEO) matrix. The Eu 3+ complexes, consisting of the central ion Eu 3+ and organic conjugate molecules, can be induced into a polarized state within the PEO matrix under an applied electric field, causing a relative displacement between the Eu 3+ ions and the organic ligands. This displacement disrupts the ligand-mediated sensitization process, leading to a reduction in fluorescence intensity, a phenomenon we term polarization quenching. Notably, upon the removal of the electric field, the relative displacement between Eu 3+ and the ligands is reversed due to depolarization, enabling the device to autonomously recover its sensitized luminescence. The process exhibits a repetitive nature. This study presents an innovative method for the dynamic regulation of fluorescence through the migration of Eu 3+ luminescent centers, highlighting substantial potential for the modulation of light emission from lanthanide metal complexes via external fields. Specifically, the visualization and retrieval of optical information can be achieved through the application and subsequent removal of an external electric field, thereby facilitating its utilization in prospective photoelectric data storage media.
研究领域:
材料科学
·
光学
·
光电信息
✓ 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）